As usual, maleficent gives great advice
First semester, get into good habits. I'll echo the advice to get your homework/studing done as early as possible. That way you have more time in the evening to hang out with friends, watch tv, play video games, whatever.
If you're living in the dorm, keep your door open while you're in there. You'll find that people will stop by more easily then if you're behind closed doors all of the time. Be friendly and make friends. College is not fun when you're a loner.
If you're so inclined join a sport or some sort of club. Go to football/basketball/baseball games. Socialize. Find the parties and go to them. But don't be stupid and go to every single party every night and neglect school work. Realize that you're there to get your education. Somebody is paying for this, don't waste their money.
But most of all, have fun and enjoy it!