If you think college is going to be a learning experience, you're right. If you think that the learning experience is going to be about particle physics or late 19th century Scandinavian literature or whatever your major is, you're only half right. What you'll also be learning about in college is people -- and how to live with them.
For most college students, dorm life will be their first experience living nearly 24 hours a day, week after week, with a community that isn't made up of people they've known their entire lives. If you're the type of person who makes friends easily, dorm life is going to be a breeze. If you aren't, then dorm life will be a bit of a shock. You'll be living side by side with all kinds of people, many of whom you would have avoided if you'd seen them coming the other way in your high school hallway. Don't look at this as a bad thing. Look at it as an opportunity to develop people skills. Some of these people may become your friends for life and, even if they don't, you'll still want to have them on your side while you're sharing a communal living space with them. Be friendly. Do favors for people. Just don't overdo it and become a suck-up. Nobody likes that.
The two most important people to make friends with are the resident assistant (RA), usually an older student or grad student who the school puts in charge of running dorm activities, and your roommate; that slightly weird and scary human being that you actually have to sleep in the same room with. And if you absolutely can't get along with your roommate -- well, that's why you made friends with the RA. Ask him or her about a roommate swap.