Having roommates can be a tough dynamic. You have to learn how to share a space respectfully. Sure, you may have shared a space with family members growing up, but living with a non-family member is different. They might have different needs and expectations when it comes to their living situation. Maybe they require a little more privacy than you’re used to giving. Maybe they don’t mind a little mess in the shared space. Maybe they really do mind. 

Maybe they love having people over, and maybe they need at least 24 hours’ notice before anyone else comes into the space. These are all things that you have to negotiate together. When I was in college, the RA of my dorm made all roommate pairs sign a contract at the beginning of the year so that they could refer back to it if they ever had a dispute. Though I thankfully never had to use it, this was a pretty good idea.