With three years of college under my belt, I'd have to say that I've learned a lot along the way. During my first year, I began to figure out what worked and what didn't, and I learned from my mistakes. Here's some advice, so you don't make the same mistakes that I did.
1. Don't bite off more than you can chew
I can't stress this enough. As a freshman, I thought it would be a great idea to take the maximum amount of credits at my college, work ten hours a week, and join several clubs. I figured that since I did well in high school that college would be the same amount of work. Soon enough, I was stressed and burned out from doing too much at once. While this may be doable for some people, I suggest that you start off more slowly than I did. If you find yourself with a lot of free time, feel free to take more classes or join another club. Make sure that you save enough time for yourself and for friends too.
2. Don't enroll in class you can't wake up for
When I was in high school, for part of the school year, I got up at 5 a.m. (for early morning swim practices). When I didn't have training, I'd wake up around 6:30 for school. I figured since I had survived this, getting up for 8 a.m. classes would be a breeze. I was so wrong. After the first few weeks of college, I couldn't wake before 10 a.m. I was staying up later than I was in high school because there was a lot more studying to do, and I am most productive at night. Don't take an 8 a.m. classes every day of the week unless you absolutely know that you can wake up in time for each class. Since coming to college, I have learned that I can take early morning class if they only occur one or two days a week.
3. You have to study a lot more
In high school, I had grown accustomed to studying very little. I was able to soak everything up in class and could do the homework relatively quickly. When exams rolled around, I felt super prepared. College, on the other hand, caught me off guard and hit me like a ton of bricks. There is so much more material to learn for college classes, and so you must take time out of your day to read the textbooks that your professors assigned, and do extra practice problems. Often on exams, I have to apply concepts that were barely touched upon in class, or needed to material inside and out to answer extensions of material we had covered.
4. Never ever skip class
Unless it's necessary, don't miss any class. There was one class during my first year that I hated. The professor was incredibly dull and the class was in the morning. I would sometimes skip the class to sleep more. I figured that since the lecture notes were online that I would be fine. While I did do well in the course, there were some things that I missed on the final that I could've gotten right had I never missed class. You never know what little detail the professor might share that could end up on an exam. I've had a professor mention their cat twice in class and then put it as a question on the final exam for extra credit. Those questions could be the difference between an A and a B. You never know, so don't risk it, and show up to class and pay attention unless you absolutely cannot attend.
5. You have to be disciplined
When I first went to college, I abused my freedom. I could stay up as late as I wanted to and do as I pleased. I ate lunch at 4 pm just because I could. However, living this way wasn't the best idea. I started staying up too late and would procrastinate studying for my first exams and would end up pulling several all-nighters. I was dead on my feet when my first semester concluded. While I'm still figuring out my schedule, I find it very helpful to put everything on google calenders. Put in times that you plan to study and stick to them. Have a set time to go to bed and wake up every day. You'll be much more productive this way.