Okay, let me start by saying that, obviously, what happens inside the classroom is extremely important. In today's world especially, grades are everything.
They are your ticket to medical school, law school, or any other type of graduate or post-graduate schooling and work. Simply put, you need good grades. However, that's not all you need. You're also a human being with a life that you should be enjoying, and college is the perfect place to begin if you haven't already.
Also, get involved on campus!! Take advantage of the plethora of opportunities that your college has to offer. Go to job/internship fairs when they are presented. Get a job in an office on campus, it's a great way to meet people in the administration and make connections with them. Join a club that interests you, and you'll be able to meet a bunch of new people who all share the same interests as you.
Living in a dorm is one of, if not the most fun parts about going to school away from home. You live with your best friends, and you're in a building of people all around your age group who walk around the same campus as you do every day, and who probably do most of the things that you do on a daily basis, too. Talk to them when you see them, you just might find something in common. Make friends and then make friends with your friends' friends. And then go make more friends. Meet as many people as you can, even if you don't exactly click with everyone you meet right away. You never know, you might be talking to the next Steve Jobs. A major part of college is meeting people and making connections because some of them might be able to help you in the future.
It is absolutely a good time for commuters, as well. Explore the area around your campus. Find a few nice restaurants and stores to blow your money in. Discover a coffee shop or two to spend time in, get your work done, and enjoy a refreshing cup of Joe. Not to mention, you can meet people who live in dorms and hang out in them to get a sense of what they are like, and you might even find yourself wanting to live in one in the upcoming semesters.
There's also plenty to do outside the classroom from an academic standpoint if that is what you're focused on doing. On most campuses, there is plenty of research being done, and getting involved simply requires sending an email and inquiring. Drama and theatre departments put on multiple plays per semester. Get over your fear and go to the auditions. Join the band, play a sport, go to the gym and find a buddy.
There is tons to do on or around every college campus, whether you live there or not, so take advantage of your opportunities and enjoy life.