I envy being handy enough to fix stuff around the house with relative ease. It's not something I've given up on completely, but I usually end up breaking stuff or otherwise somehow making the situation worse even after researching and perfectly understanding the procedure. I've even damaged a lawnmower just trying to mow the lawn.
You seem to have embraced the first aspect "it is fucked anyway so might as well have a look". This is good as many need to be pushed into that to start this out.
When reverse engineering items despite pulling apart maybe 1000 items so far this year (it has been a light year) and many many more times that since I was a kid, all my books covering how things work (said books starting in the 1930s and going from there) I still take it section by section trying to understand first the high level aspects of components and the nature of their interconnection before drilling down further.
Too often when I see repair tutorials it is just a technique to effect a repair rather than give an understanding of what is actually being done and reasoning for the steps. Sometimes a technique is nice to know if they hid a screw somewhere or used a sneaky snap tab on a case, or maybe a wire/ribbon that might be damaged, but try to get to the point where you can see a high level overview of the system. Makes life so much easier if you want to fix things.
As far as round the house.
If you have plasterboard/sheetrock and want to attach something to it then
https://www.ironmongerydirect.co.uk...d-plug-jar-of-400-plugs-and-400-screws-491403
They are absolutely wonderful if your item covers it enough (most things will) and much much much prefer them to any other type of fixing I have seen or used. Just remember to cut the included screw down if you are going flush with the board/wall. On cutting screws then I will cheap out on many things but get yourself a really nice set (I like the knipex red handled ones) of side cutters and you will see the difference.
If you are pulling out a nail then put a sacrificial board underneath it so it gets marred up rather than your furniture.
Epoxy resin to bond broken ceramics is cheap (the tables you see on the internet are not but eh) so get some of that and keep the superglue for sticking yourself back together when said broken ceramics cut you.
Electronics wise. Check fuses, check capacitors (big ones will keep power so be wary of them, you don't necessarily need an ESR meter as bulges and leaks give it away most of the time), check switches, check connectors, check for any nasty smoke stains, check for any leaks that cut a track or left a short somewhere, if optical drives then 90% of the time it is dust on the laser assembly so get in there with a cotton bud carefully. This is 95% of electronics repair, 4% is if nasty smoke stain/exploded chip is a thing then see if it is a non programmed part (programmable stuff is increasingly common but not dominant) and replace that and the 1% is actually hard stuff you might need some skills and tools to diagnose (though that starts with "thou shall check voltages", even if that is actually what you probably did above).
Automatic wire strippers (
https://www.consumerunitworld.co.uk/ck-495001-automatic-wire-stripper-3476-p.asp is my preferred style) are good stuff, leave the cheapo ones and your teeth alone. Similarly whoever invented wire nuts is second on my list after the one that decided not to include cables* with printers any more.
Also
plus everything else in that series and his older series as well for that matter (all on the same channel).
I live in the UK where replacing a plug or a lead is a 30 second job, and a box end is 2 minutes with 5-7 screws involved but if you are in the US it is still possible
*if you are heading down this path in life then it is mandatory to have a box/bag/whatever full of random cables that people might need. It will drive almost any women in your life absolutely nuts (it is like a whole rolling mass of untidy wires waiting to spring out and do whatever it is they fear will happen) but power through it.
Grinder and paint make you the welder you ain't is a common mantra, similar things exist for all manner of other aspects though for household purposes see "needle files" as they can be used to hide all manner of butchery to plastics. While you are buying needle files the same place will sell you picks so get even a cheap set of those, and if you are pushing the boat out then a set of a pin punches.
https://www.instructables.com/When-a-Phillips-is-not-a-Phillips/
You can turn a philips with a posidrive and vice versa. Unless you are in a cheesy film plot or hanging upside down by your ankles in somewhere unpleasant then get the right one. So many people don't and wonder why it is hard/the thing is camming out and rounding over.
Learn to hold a saw properly. As in hold it like a gun with your finger steadying it -- the wrap your hand around it and nothing else approach many employ just leaves you liable to be injured when it jumps out the cut. Related to this is also position your body. Don't saw upside down hanging on by your ankles -- work holding and positioning make life 1000 times easier if you get it right with most injuries and failures happening when not (sometimes you have to, try to minimise that).
Filling holes in wood is doable as well -- beeswax as well as glue mixed with sawdust being the primary two methods that cover most use cases. Said beeswax if melted and mixed with a tiny bit of turpentine to form a sort of paste makes an absolutely wonderful polish as well that will reawaken tired old wood better than most pills and potions I have ever used or seen used.
Similarly you don't have to make it through something in one cut with a knife. Take multiple even if you have a sharp knife.
Making holes larger with a drill is annoying, especially in plastics and thin sheet metals. Get a handyman's reamer/tapered reamer.
Every man should own a good vice/vise, or at least a vice. Also really helps with that work holding thing.
Plumbing. If it involves gas, steam, high pressure or hydraulics then leave it to someone that knows what is up as it can easily kill you. If it is just water at sensible pressures and temperatures then more fun is available.
Modern plumbing is moving away from copper (good reasons and bad) but that makes life easier still in many ways. Pipe caps and pipe connectors plus a few lengths of pipe in suitable diameter are cheap and will keep the water flowing or indeed not flowing when stopcocks and other means failed you and the plumber is days away. PTFE tape is good stuff to have (put it around that which is supposed to seal the water in, which is not always the threads -- learn what a plumbing olive is). Taps work in all manner of methods these days but tap washers are cheap and worth having a set around. Get a reasonably nice pipe cutter as well as they are basically considered disposable items. If pushing the boat out then pipe clamps are worth having.
