Hey, Awkwardo!
I'm going to be starting my fourth year of college in September, so I guess I could say a thing or two.
One thing I noticed was that once kids enter college, they lose a bit of self-control and judgement. I guess after living with your parents for 18 years freedom can be incredibly refreshing... However, no matter what, breaking rules is never a good idea. You'll probably experience a lot of peer pressure in college, especially freshman year, to drink alcohol or do drugs. It's easier said than done but don't give in. I've known quite a few people who have been caught hiding alcohol and have been suspended or worse. Silly mistakes like those are not worth your education. Also, silly mistakes extend to other things as well. For example, a very close friend of mine was caught torrenting something on our school network. Just really try to be aware of what you're doing because once you're caught, that mistake isn't going away. You probably have heard/know all this, but I thought I'd include it for good measure.
Now, onto life advice: college is really the last opportunity you will have to be a kid. Enjoy it while it lasts. Of course your grades are really important, but what's equally (or maybe even more important) is that you do what you want while you still can. Pick up a new instrument or go to a concert. Things like these won't be as easy to do once your working life begins. It's important to work hard but don't forget to take time for yourself. College can become very stressful especially since the workload is larger and there is far more competition. Remember to pace yourself. Lots of kids become depressed and anxious. When you find yourself facing a problem, ask yourself if you know what the solution is. If you do, then what's the point of worrying about it if you know how to fix it? If you don't know how to fix it, well then obviously it is out of your control -- so there's no need worrying about it.
The people who worry the most also tend to be procrastinators... so, try not to procrastinate. It's easy to get anxious and think about what you need to do than actually doing it. If you can't focus now, don't worry, do something else - go to the gym, hang out with friends - there will be a time in the day where you can slow down and get your work done. Basically, there's a time for everything as long as you're not devoting hours to a single thing (procrastinating, working out, partying). Relax, relax, relax. Having a good mindset and attitude is far better than (and in many cases more efficient and mentally healthier) working day and night.
Last thing I'd like to say is that it's important never to forget your friends. College life is busy and full of changes, but don't let that get in the way of your friendships. College is probably one of the last places you can build lasting friendships (ex. with your roommates and classmates, people that you live in the same community with and see almost everyday), and once those people graduate and leave, well, they're going to be gone for quite a good while. One of my greatest regrets over the past four years is not spending enough time with my freshman year roommate. We were roommates for three years and were very good friends. However, I moved off campus to live on my own a year and a half ago and I barely saw her (due to the distance and schedule differences). I'm sure if both of us tried harder we could've spent a lot more time together, but the truth is that we only saw each other two or three times. We both missed out on very important events in our lives (ex. her graduation, birthdays, etc.) and there's nothing we can do to fix that. Now, my friend has graduated and left to work in a different state. I don't know when I will see her again. When you make a good friend, make sure that you keep in touch with them and don't let that friendship go to waste. There will be a time over the next few years where you feel sad, or perhaps discourage, or maybe even heartbroken, and your family won't necessarily be there to support you - but your friends will. Friends are so important in college, especially because you're away from home. Don't take them for granted and don't forget about them.
I hope that some of this advice will be helpful, and I wish you the best this fall.