College is a proving ground. By the time you hit college, you think you know who you are, what you believe in, what you think is important, and how the world works. That's all based on your life up to that point and whatever experiences you had, wherever you came from. Now you're thrown into a bigger pool, with new and different people from different places with different thoughts and different ways of doing things. Maybe even radically different. You get a chance to test your ideas and beliefs against those of others, whether that be in classroom discussions, cafes, or late, late nights in the common room. Some people's pre-college identity withstands the testing and they come out exactly the same. Some people totally change. Most people fall somewhere in between.
Grades are important. Tests are important. Class, not so much (I'd say differently if you were on a STEM track). Study for tests, do the reading at some point, make extra sure you go to the review sessions before a midterm or final. But any individual lecture? Screw it. There's a lot more to life, and especially college life, than sitting in a lecture hall listening to somebody drone on about the importance of 18th century Germans, or how Gone With The Wind is full of secret freemason references, or why rabbits shouldn't be classified as rodents (they're lagomorphs). Don't sweat missing any individual class, or even many classes, if there is a more interesting alternative. Exceptions: any early attendance that is necessary to make sure you do not get dropped from the class, such as in popular impacted classes, and again those crucial pre-midterm and pre-final review sessions.
Meet people, talk to them. That's how you test yourself against the world. If you come in as a studious, anti-social nerd and spend all your time outside of class living alone and studying, you're not getting the college experience. Meet people in class, in dorms, in frats, at sporting events, in cafes, in social clubs. The opportunity to meet a wide variety of people with different perspectives is one of the most valuable things about college. Before you get there, you had the time but not the breadth of perspectives to use as sounding boards. Once you leave, you'll have the breadth of perspectives, but not the time.
Your roommate in all likelihood is just a regular dude like you. If you're lucky, you'll become lifelong buds. If you're unlucky, you'll hate each other and move on after a year. Either way, it's a good life experience. There has to be some level of initial trust because you live together. That doesn't mean you have to leave cash lying around in the open on the first day. Also, your roomie may be trustworthy but that doesn't mean that his friends/guests necessarily are.
In a few months, you're probably going to say you go to U-Dub River Falls or UWRF.