Nice timing! (Just got back in from a run myself, haha)
Along with the comments above, run as much as you can, once a day if possible. I personally like tracking my progress and bought some
stupid little Nike+ wristband thing that works with my
shoe that lets me chart all that. There are a ton of free and dirt cheap apps out there for Android and iOS that do the same thing, work with your phone's GPS to track your progress and give you stats such as how long your run was, how many miles you ran, calories burned, average mile time, etc. (
I recommend Endomondo if you're on Android)
Its nice to see the stats side-by-side at the end of everyday's run and see how much you're improving (you can only get better, faster, and gain more stamina, nowhere to go but up!).
Otherwise, if you don't want to be bothered with all of that, I would just recommend bringing along some sort of stopwatch and setting a goal when practicing, such as running a full lap around a really long block or something (in my case, I use the average time it took me to run 1 mile from each session). Run the lap, clock your time, and try to shave it down more and more. Keep track of your best time (and worst) at the end of that day and try to beat it at the start of each new day's session! You'll see yourself start to gradually get better and you'll feel yourself getting better too. Your legs will start to take a more fit shape, your breathing and endurance will become easier. Not to mention, your body will start to feel good as a whole, as well. After a good run, your body may feel a bit tired, but once you cool down and bounce back, you'll feel light as a feather and your body will feel better overall. It's hard to explain, but you'll know what I mean once you start running.
Also, make sure you have a good shoe. It doesn't need to be anything state of the art, just make sure it doesn't make your feet feel uncomfortable, you want something that will help your feet, not hinder them and make you want to run less or cut off a running session early because your feet hurt. Lastly, if you develop a running schedule, STICK TO IT. If you start a solid schedule, then start to miss some days here and there irregularly, your body might start to hate you. And all that progress you've made will slowly start to roll backwards. Some days you won't feel like running at all, but just get out to your running area and just run a little less if you have to. Its about staying active on a schedule your body can get used to.
In many ways, running is like a video game, in which you're constantly trying to improve your own stats, shatter new goals you set, and ultimately beat yourself (lolgross). Its pretty fun, gets you in shape, and doesn't require a lot of time! Plus chicks dig runners. AND there's tons of hot runner chicks. In those little tight, tight running shorts. Tight shorts. Just, do it man.