I'm a quiet guy too and I'm off to start college in 4 weeks myself. I went to a college orientation not too long ago and it was a good experience. You're not the only person that's new, everyone else is just starting out and trying to make friends. I hope you're living in the dorms because that will help a lot. I'm actually trying to make myself live in a tiny TRIPLE (which could either be very good or very bad

) because I know if I live off campus I will most likely isolate myself. (I could turn this into a very long rant lol).
It's also important that you make yourself go out and do stuff IN THE BEGINNING of the school year, right when you get there because thats when the most friendships and bonds will be made.
And as other people said, confidence! At my orientation I saw that the chicks at my college are ugly. You'd think it's a bad thing but it only made me realize how hot I really am

P). After that, the chicks came to me. Relationships will be formed and once my standards lower it will all be good. In your school they may not be ugly. Maybe just pretend that they are
Be optimistic. Force yourself to be more outgoing and confident, and do it from the very beginning. You're starting fresh in a new place with new people. Now is your opportunity to turn yourself around with just a small push from the start. Good luck bro.