Hey babe! You are going to love college. Believe me.
I was really scared too, everyone is! It's because.. unlike before.. where everyone you know just kept moving on to the next school.. EVERYONE is going to be different. It's a new stage in life and it sucks to change, but it happens. All you have to do is keep looking straight and smile! I promise.
I'm glad you will be dorming! You make a LOT of friends that way and hopefully you'll click with your roommate! People who start off by living off campus have a much harder time blending into the social life. And! Another way of making friends is to join a few clubs that you're interested in. In the first few weeks, there should be some club day events were you can check out ALL of the clubs. And how do you start meeting most people? You do so by finding a common interest, i.e. a club!
You could also look into rushing a sorority, but since you're introverted, it might not be the best idea. But! College is a time for checking out new things, and in a sorority you DO meet a lot of people and if you're in one, you're in a family and you have sisters as well. Sororities are intended for you to meet people and make friends, have a family away from family. Even though there are all those rumors of "sororities" you may just have to find a right one. But if you don't want to rush, then don't, but you may want to check it out. A suggestion.
That doesn't make leaving any better though. Things do change. You won't get to see your back home friends all the time like you did before, even when you come back for the summer. But if nothing has changed when you do come back, that means it was true friendship. You tend to live a double life, one at college, and one when you get back home, and that's totally fine. The worst part about leaving was when.. everytime I went to hang out with my friends before we all went to college is that the group got smaller and smaller as summer went on. It's really sad.
My best friend goes to UCDavis in NorCal, while I go to UCLA in SoCal.
Just make sure you make the best of the time you have left and you won't regret it, promise.
And about parties. There are ALWAYS different kinds of party. If you're apprehensive about frat parties or parties that have alcohol, DO NOT go to them. No one is forcing you to. You DON'T meet people that way because you don't meet people when they're drunk, you meet DRUNK PEOPLE. I've had little food parties with my friends or people from my dorm building, I've went on coffee runs with them.. we have little parties like that as well. We've even had little dance parties in our dorm! And if you DO go to a party, make sure you go with people you are comfortable with and who will take care of you. Even if you are introverted and quiet, doesn't mean everyone at college is outgoing either. You WILL make friends and even if it takes you longer than others, don't be discouraged because if they won't be your friends, those are not people you want to be friends with.
And who knows, if you meet the right people, they may be able to bring you out of your shell and make you outgoing! You never know! College is really when you learn to grow up, believe me.
Also, if you get a job, you'll make friends too.
Coworkers are some of the funnest people to hang out with, at least for me.
Best advice of all is to HAVE FUN. Don't change who you are just to make friends. Stay yourself, you WILL have fun, you WILL love college. Not to be cliche, but it some of the best years in your life.
I hope that helps you out, you will be fine!