Well, first year is tough, because you don't really get to pikc your roommate, if you live on campus. And as someone else said, you usually don't get a choice and have to live on campus for at least one year. That was the policy at my school. To a degree, you'll just have to deal with your roommate and work out compromises. But things get too bad, you can speak to your floor's Resident Advisor and request a room change.
As for the colleges, it's OK if you don't know what major you want. A lot of students don't, and sometimes they even change their major. Now if you have an Idea of what you might want to pursue, you might pick a school with a stronger background in those areas. But honestly, undergraduate programs are all pretty much the same. You might also consider taking general education classes at a lesser known college, and transfer into a college that fits your major better after two years. And so it's OK if you don't know your major just yet. Because you can just take gen ed classes at a local college. By the time you are a sophmore or junior, especially junior, you should have an idea of what you want to focus on. At that point, transfer to a good university and take major specific classes.
As far as choosing a college, look beyond it's academic credentials. Look to what's the teacher/student ratio, what campus organizations are there? How much cultural diversity is there? Religious organizations (if you are so inclined). Campus life in general, how many parties, bars per square mile, etc...
HTH
Xin Li