Have fun with whatever you do. I just finished my first week of my fourth year.
Girlfriend of 2 1/2 years broke up with me a week before classes started. And honestly, 2 weeks later I could care less Get out and meet girls, party if that's your thing, and pursue absolutely anything you have the slightest interest in. College is the time to develop who you are.
I just signed up for the school's motorsport club on a side note!