Step 1. All the fancy hedge fund traders with millions (if not billions) to invest, all the education, all the staff, all the computers... they rarely beat the baseline stock market consistently. That is to say buy one of every share (there are things called ETFs, exchange traded funds, that allow you to buy in fractionals of a pool of just that minus their tiny cut) and you will be doing better than most high end professional finance/investor people.
SPY (
https://finance.yahoo.com/quote/SPY ) being the main one for the S&P500 aka main US stock market, NASDAQ is mostly tech focused and prone to larger swings, IWM is Russel 2000 which is mostly small business stocks and considered a sign of health in the general economy where the SPY featuring Apple at some notable percentage
https://www.investopedia.com/top-10-s-and-p-500-stocks-by-index-weight-4843111 means if Apple slaughtered some babies rather than the usual 8 year old slave labour getting mangled in the factories it might change the entire market that day (and if Amazon, Google, Microsoft and Tesla all get shown to be using the same processes then oh dear).
https://finance.yahoo.com/quote/IWM https://finance.yahoo.com/quote/^IXIC?p=^IXIC
6 to 7% per year is the historical rate of the basic S&P 500, by no means a guarantee of future performance (indeed we are staring down the barrel of something quite serious on the downside), but if inflation remains at 2-3% per year (right now we are doing crazy high inflation as money printer go brr, which appears to be sticking so play that as you will) then in a few decades that is a nice retirement. That is also the baseline to beat, though again you will mostly want to be beating inflation (which sticking it in a bank account and sticking it under the mattress does not do and thus your money is worth less and less each year). You can also skip whole market and go for segments. You can also trade in items aka commodities like oil, natural gas, lumber, lean hogs, feeder cattle, gold, silver, copper... if you want to go that way.
You make money two ways (plus another we will cover a bit later). One is buying low and selling high. Figure you which stocks are either going to go do good things or are valued way under what they should be (3 years of profits is a sort of rule of thumb but that is not always the case). Two is dividends. Here some (but not all) companies will take a portion of profits each year and distribute it to the share holders (though not all shares even in such companies will get this, we will leave that for today though as that is mostly a high end investment concept when you are investing millions into a company). Said shares might also entitle you to vote at company meetings and on direction of companies.
You are a puny mortal as well so you don't speak to the stock market, instead you speak to a broker who has paid the required fees and done all the tests to play. Classically they would take a percentage of the trades you asked them to do, though in the age of phones there are zero commission brokers (you may have even heard of them) which tend to make their money either with the gamblers on their service or selling on your trades so someone can get ahead of them and make fractions of a penny (but do that a few billion times and you have real money).
You can also do something called spread betting but... no.
The US markets tend to be the reference for the world. Anything that is not that then varies -- rich parts of Europe have a more or less functioning economy, as does the UK, as do places people want to live (Australia, Canada, New Zealand...), Japan is an odd one as it has been having a bit of stagnation in recent decades. Anything else is a wild gamble really (China, India, rest of Asia, Russia, middle East, Africa, south America... all corrupt as you like) but if you can get in on the up swing you could make some serious money as said corruption means companies have to pay serious rates. If you are investing in such places it is either said gambling, you have inside knowledge, blind and stupid patriotism or said corruption means your only investment opportunities are within the country (Iran is fairly noted for this, lesser examples might be tax breaks given to people that invest internally rather than just doing the US).
You can do this long term (has some tax implications as well) or short term (see day trading). While I noted all the education, computers, staff and such above then some will skip deep research (said research being fundamentals trading) and instead know nothing of the underlying business (indeed knowing is bad for some of them) and just look at charts (this is called technicals trading, see also macd and RSI which is moving average convergence divergence and relative strength index respectively) and play accordingly. Some go even further into the technicals world and then you are dealing in quant fund territory
https://www.investopedia.com/terms/q/quantfund.asp (shockingly enough this is where I like to ponder things but I really like numbers). All sorts of other numbers can be used in determining things here; inflation numbers (whether the ones provided by the government, which lies because they have every reason to want them low but not negative, or something compiled by someone else is up to you), employment numbers, layoffs numbers
https://layoffs.fyi/ , house prices*, sale of pet toys**, car park capacity in big shops satellite imagery***, ...
*oh and you can invest in housing too, indeed some do "real estate investment trusts" which buy up and manage real estate, hopefully in multiple places such that factory closing down does not kill a town and with it your entire property portfolio, paying out on profits from rentals and sales there.
**I am not kidding. I am broke so Fido can play with the tennis ball he found in the park rather than $20 on a squeaky dinosaur/duck/squirrel is a real thing and pretty reliable as an indicator of the health of the economy.
***still not kidding.
https://www.theatlantic.com/magazine/archive/2019/05/stock-value-satellite-images-investing/586009/
Bonds and options markets then.
The government issues bonds, and so can companies but we will leave that for now (not to mention it works much the same way). Terms can vary a bit (bills, bonds, gilts) depending where you are but generally some government related entity will offer to pay a given percentage out over the next however many years but they then get some money to pay for roads/hospitals/guns/drugs for their party/... (indeed some would say this is how things are funded, your taxes might as well be set on fire for all the good they do. Combine that with "the country is too big to fail so let's print money forever as there is no downside" and you get something called MMT aka modern monetary theory, sadly it is a thought pattern that infects various politicians and their operatives in central banks at times). No bond is ever likely to be more than inflation but said hedge funds are often obliged to buy into it, also still better than leaving things as cash you get that bit of interest on it yourself in the meantime. If a government does not pay its bonds it is extremely bad news for that government as nobody will want to do business there, and thus why places that are not likely to collapse (the US may or may not be on the decline but probably not going to get taken over by somewhere else or have a non functioning government too soon) get away with low rates but wanting to invest in corruptistan will see them pay more out but also be more likely to not be there.
Related to this is when you hear central banks setting an interest rate this is arguably that -- a bank can charge whatever interest on a loan they like but why risk Bob getting hit by a bus and not paying the rest of the car loan/mortgage/whatever then the super stable government is offering more, Bob then getting higher interest rates on new loans, new renewals and hopefully cutting spending down to cool off inflation to tempt the investors away from government bonds.
Company bonds are similar but instead you are betting on Sony's likelihood to go bankrupt rather than a government.
Some will then split their investment portfolio between bonds and stocks to keep that baseline growth going while the stock market is decreasing in value.
It is not all fixed timelines a well, and this is where the yield curve inversion you might have heard of comes in. If the 5 year timeline out pays the 10 year one (longer time usually means more money) then that is usually a sign that bad times are ahead.
https://www.investopedia.com/terms/i/invertedyieldcurve.asp
Options markets.
Calls and puts. Calls are I offer to sell you 10 shares (it is usually a multiple of 10) next week at a certain price. If the final price (which I as the one doing this bet might be able to manipulate, indeed big trades might even manipulate the price by virtue of me maybe buying some up in case the price does shoot up) is above that price you bet me last week then you have a contract you can sell on to someone that can buy them (10 shares in some companies is a lot of money) or actually buy them to in turn sell on (or keep if you want). If the price is below the price you bet then you could waste your money and still buy them at the price agreed (why do that when the normal market will sell you them for less) or more likely you let it expire worthless and lose everything.
Puts are the reverse and you are betting on the price going down below a certain amount instead.
There is also the related concept of short selling wherein you borrow a stock, sell it this week and give it back next week (hopefully having bought it back when the price has dropped). This would be the third way and how you make money when the market/a given company you are interested in is going down. This is part of what saw Gamestop rise ridiculously the other year, and the margin calls (you can't just do it, aka naked short selling, in most markets as you need to arrange insurance of a sort, said insurance might still doubt your ability to pay up at the end so ask for more money in case you fail which is what a margin call is) then bankrupted a few big hedge funds (and other times such people getting caught out have to sell off other stock.
Potential profits in these options trades are accordingly quite a bit higher to reflect the increased risk. Originally they were an insurance mechanism but today many use it as gambling effectively and where the wall street bets come in and where people lose as much as they do. If you have a tighter range you can do spreads where you buy options from others and sell options to others.
People also watch these markets (much like normal stock trades these tend to be published so you know what, when and where but not who and why) as you can find insider trading and that some firm thinks they are onto a real winner with the trade.
You can trade in money and the exchange rates thereof, this is called foreign exchange aka forex. Potential numbers are huge but it is also said nobody actually makes money doing it and anybody that claims to is a scam artist.
I should also note economics is a social science rather than a hard science; follow my chemistry instructions and you will get a result I say you will, economics has no such clear lines in the sand. To that end you can ponder the variously conflicting schools of thought here.
"This is hard I want to watch a video". Plenty out there covering basics for which I gave terms, if you want to watch something more in action then I actually really like this guy's videos
https://www.youtube.com/c/TheMaverickofWallStreet
Bunch more
https://gbatemp.net/threads/your-favourite-finance-economics-video-channels.612072/
