If you are a single child like me and this is your first time out of your house you will understand the problems of getting used to living with someone.
When I first moved into my shared room I was secretly praying for a neat roommate because there is nothing worse than coming back to your room after a long day and finding a mess on your side of the room too. It took me almost three months to start talking to my roommate freely. Before that I guess both of us didn't trust each other enough.
But now after three years we are best of friends.
Here are a few points to help you get used to the idea of living with someone:
1)Your roommate is also human and is probably as scared as you are with the idea of living with someone. Try to break the ice yourself.
2)Try to clear the air regarding friends coming over late at night, when you want lights off etc. as soon as you move in. This will help in avoiding confrontations later.
3)If their is something that your roommate is doing that you don't like tell him/her about it instead of harbouring a grudge against him/her. You have to live with the same person for a couple of years atleast.
4)Talk. I cannot stress this point enough. Its best if your roommate is your confidante because that way you can talk to him/her about anything thats troubling you or on your mind.