I felt it was time to give advice once again, since I've finished my sophomore year. Obviously not everyone's experience at college will be the same, since many of you won't attend a Christian liberal arts university in a town with two stoplights, but that's semantics. So let me launch into my advice.
Continue avoiding those 8 a.m. classes like the plague. You'll thank me later.
If your dorm has a kitchen, stock up on ingredients for things that are easy to cook - Kraft macaroni and cheese, ramen (buy some vegetables to cut up and toss in while you're at it), grilled cheese, scrambled eggs, and pasta with sauce.
If you haven't already, join a club/group of some sort. Check out what your university has to offer, intramural-wise, if you're at all athletic but don't want to be on an official team. See if your major has an honors society. Try out for a play. If your university has an co-curricular fair at the beginning of the year, go to it. It's a great opportunity to see what's available (and you can often acquire free T-shirts).
Realize your classes will likely be harder. By your sophomore year, you're (hopefully) taking more classes for your major and minor and, in addition, you can start taking 300-level courses. These will require more effort and time, and, if they're for your major, you'll want to devote time to them.
Besides big events, see what else your campus has to offer - like video game tournaments, hall outings, and concerts (put on by the music majors and various music groups).
Make time to read at least one book a month for pleasure. Instead of watching Netflix or playing video games, pull out a book and relax. You'll form habits that'll last you a lifetime. The average adult is only reading five books a year (*tries not to cry*); if you read one a month, besides reading for school, than you'll have read twice as many as the average adult!
Make new friends. You don't always keep the friends you make in freshman year. I'm fortunate to have kept several of them (including Former Roomie), but even though friend groups have mostly formed, you can still make new friends! I did this year. This is another good reason for finding new/more co-curriculars. You'll meet people with similar interests!
Stay organized. Make to-do lists, but accept you won't be able to accomplish everything on it in one day. Keep a planner, even if it's only to list quizzes, exams, and projects (I don't put every single homework assignment in mine).
Keep your room clean. I tidy mine once a week so the mess isn't terrible. I accept that my desk will never be neat, but I can at least pick up the piles of clothing and what-not on the floor, do laundry, and wash dishes.
Let go of stress. It gets hard, I know. I got so stressed out this past semester that I caught a cold. Just try your hardest and know that sometimes you need a mental health day or you need to leave something on your to-do list for later.
On a related note, try not to procrastinate too much. This creates stress and situations where you can't take a breather and leave something to do later. Also, procrastination means you can't always do spontaneous things with your friends, which will make you feel sad and left out.
I'm going to repeat some advice from last year. If you find a significant other, DO NOT NEGLECT YOUR FRIENDSHIPS. Yes, your romantic partner is important to you and you should get to know them better and spend time with them. But having a girls' (or guys') day or night with your friends is important, too, especially if several of your friends are still single. They want to spend time with you - not you and your significant other.
Start looking for internships. You can sometimes get internships in the summer between your freshman and sophomore years, but it's often easier to get one once you're a rising junior. That doesn't mean you can't look, though, especially since application season usually starts in January. Explore options in your desired career field, and you'll be surprised what you can find.
Get a job. Even if your parents are as rich as Midas, find a job. It'll probably be minimum-wage and/or physical labor, but you'll be earning money that's all your own. Otherwise, you'll have to continually turn down invitations to go out to eat or shop.
Jumping off of that, put aside at least 25% of your paycheck for something special. Save that money for a weekend trip with friends, or for the summer, or for a day when you need to treat yo'self. You'll thank me later.
Keep having fun. Keep making good choices, but keep making mistakes, too. You'll be stronger for it. Don't beat yourself up for those mistakes, either. Apologize (if the situation calls for it), learn from it, and move on. And once you finish this year? You'll be an upperclassman and halfway done with your college education. (Unless you're going on to grad school. If so, you have my condolences.)
P.S. If you're an incoming freshman, here's the letter I wrote to you last year.