Congratulations on being accepted into the best university. I'm sure that everyone back home is very, very proud. I totally get why you bought twenty college shirts, four pairs of sweatpants, three plastic water bottles, and an obnoxious back pack, all in school colors.
You must be pretty intelligent to have been accepted. Kudos for that. Please note, however, that everyone else sitting in class with you is smart as well. We all took advanced placement courses, we all scored well on the SATs, and, quite frankly, a lot of us won state championships.
Remember this when you introduce yourself to the student sitting next to you in, say, your economics recitation. You do not need to explain that you took both AP Micro and Macroeconomics. Or that you scored a five on your BC calculus exam. Or that you were the valedictorian. You're in college now. This isn't high school. No one cares that you were inducted into the National Honor Society.
Once class begins, refrain from yelling out the answers. Especially if you are wrong. Raise your hand politely, and wait to be called on. If the teaching assistant asks if anyone has a question, do not ask a question to simply ask a question. For instance, do not ask for the TA to clarify what the professor meant when he said "weighted equally." Weighted equally means that everything is weighted equally!
If you are in a class with upperclassmen, please do not try to be cool and smart and show off. It is downright annoying. Chances are, you Know-It-Alls do not know it all. Pretend for a minute how it would feel if you were in a classroom with younger students who were trying to monopolize the classroom. Exactly.
Have a great year!