This year, I got lucky and ended up having one of my best friends also be my roommate. For a lot of people though, the roommate process is like playing Russian Roulette and hoping you'll end up with someone you like, or at least not hate. Your first college roommate is indeed one of the most important relationships in your life. And unfortunately, if you don't get along with them, you may be stuck with them for a while.
One of the most important things in establishing a relationship with your roommate is establishing expectations and boundaries. For instance, whether you both want a really clean room, and if so what will the cleaning schedule be, or what time the lights should go off, and all the things you think there might be disagreements about. Once you've established these boundaries or rules, it's important to stick to them.
You have to be ready to compromise. At home, your mom may have been okay with you letting the trash pile up or leaving your underwear all over the place, but that might not be so with your roommate, especially when it comes to shared spaces like a bathroom. Keep things relatively clean and tidy.
While it's important to talk to your roommate and form a connection by seeing what you have in common, it's important that you branch out and make other friends in classes and clubs. While you can be good friends with your roommate, it's vital to have social connections outside of that one person.
If worst comes to worst and your roommate ends up being really hard to get along with despite your best efforts, you can talk to an RA or an authority in your dorm if the roommate is doing things that interfere with your life directly. Otherwise, your roommate may just be grumpy, standoffish, or otherwise not really interested in forming a relationship with you. In which case, just be civil and keep to your roommate agreements and rules.
If you do get along with your roommate and have a good relationship with them, however, you may have a buddy for a long time to come.