It's been awhile since I was in college myself, but I'm a college professor, so I am around college students a lot. I think you need to "be yourself" whoever that is, but also understand that you are in the midst of finding out who you are. We are all on that journey to some extent, but someone your age is in the thick of it. So, I'd recommend the following:
1. Be open and friendly to everyone you meet, but don't latch on too quickly. Use some discernment.
2. Worry more about being authentic than about being liked. Seek to deal honestly with people as much as you can.
3. Listen to what people are saying and how they are acting with the desire to understand them, even if they do not understand you or reject you. This will make you a better person overall.
4. Turn the other cheek, but learn from your mistakes, rejection, and disappointments. Holding grudges helps no one, but learning to avoid putting your trust in the wrong people helps immensely.
5. New opportunities often come disguised as problems. You can't fix other people, but you can seek to "be the change you want to see."
Good luck as you move into a new year at school. That time goes by quickly, so make the most of it, keeping in mind that SOME choices have long lasting consequences (tattoo anyone?). Reminding yourself of that before you do something may affect your approach to a situation, person, opportunity, or rejection and keep it in perspective.
Mostly, enjoy this time.