Because it's relevant to your question, I'll just repost (with a few slight edits) several posts I made in a similar thread many months ago:
"I'm 24, and finally winding up my own college career (I'll be done in a few weeks. Woohoo!) I didn't figure out what I wanted to do until a few years ago, and had been pretty much winging it until then. I still am, kind of. But finally,
finally I feel that I'm at a point in my life where real "adulthood" is in sight for me. Just recently everything's begun "clicking" for me. It takes a while; give it some time. I've stayed in-state and still live at home, so I can't help you out much with dorm life -- but everyone else here can help you out with that.
Fortunately, I've always gotten along fabulously with my parents, so living with them has never been an issue for me. Besides, the food's better and rent's cheaper. Hee.
Also, don't be afraid to take time off from school, if you think you need to. There'll always be someone who'll say, "Don't take time off, or you won't go back!" Bullshit, says I. I've taken two semesters off, both at separate times, and now I'm about ready to graduate. Sometimes it's good to just work for a while, maybe travel a little. And there's nothing like waiting tables for six months to remind yourself that you'd much rather have a college degree.
Sometimes it's the smartest thing to do. I go to Georgia State University, which is in downtown Atlanta. It's a commuter college, which was probably the best thing for me. Had I gone to the University of Georgia (which is in Athens, a major college/party town) and lived on campus, god knows what kind of trouble I'd have gotten myself into. At the very least, partying would have made my grades slip. But that's just me and my own personality; just take some care with that stuff your first year, because I've heard a few horror stories about smart people pulling a 1.0 their first year because they partied so much and spent the next three years busting their ass to pull their GPA back up. Since you're going to a small college, it shouldn't be much of an issue.
Oh, and speaking of which -- don't fear getting a B once you're in college (I'm not sure what kind of grades you get, but the original advice I gave was to the fabulous AtomicBono, who is a straight-A student.) I was a straight-A student in high school and freaked out at the possibility of tarnishing my GPA. In high school I rarely needed to study to get good grades, but then got slapped back to reality in college. Heh. It wasn't that it was difficult, it was just a level of effort that I wasn't used to. Of course, that only applies to some classes -- "Legal Issues for Law Enforcement Personnel," I'm looking at you. Others are walks in the park. But yeah, do not fear the B (or the occasional C.) The B is your friend.
My advice biggest piece of advice: don't declare another major right away. I started out as a business major, then switched to journalism, contemplated economics, and finally settled on Criminal Justice. For the first few years, you'll still be getting your core curriculum out of the way anyways, so your major won't matter. You'll have plenty of time to think about it, and talk to other students (or your student advisor) about what kind of career path would be best for you. And because it can't be repeated enough: talk to as many people as you can about that!
As far as the difficulty of your classes:
You'll probably find some classes that are easier than any high school class you've taken, because professors generally don't give homework. Two or three exams through the whole semester, and that's it -- your entire grade based on those tests. That idea might freak you out a bit ("but what if I bomb one of the exams? I'm screwed!"), but don't let it. I promise it's not that bad. Study for a half-hour a day for a few days beforehand, and you should be good to go.
You'll also find that in most of your courses (at least 80% of mine, anyways), you won't need to do the assigned readings. After the first week of classes, you'll know which ones you need to read and which ones you don't -- also, there are a lot of "Grade Your Professor" sites online, so you can find out which profs are good and which ones run their classes like the SS. College textbooks are freaking huge, and it will be impossible for the professors to test you on everything in them. They'll usually only test you on things they go over in class, so if you pay attention and are a good note-taker, you're golden. And nearly every professor I've ever had either gives students study guides for exams or spends the class before the exam going over the material you'll need to know.
Hell, a lot of profs who do give essay questions will tell you what they are in advance! And I've had more than a few who, in the class period before the test, will actually pull out a copy of the exam and read straight off of it to let the students know what material it covers.
Generally, you'll have one or maybe two "difficult" classes per semester, and the rest will be a breeze. I'll spend about an hour studying for any given exam the night before, and that works just fine for me. And honestly, if you enjoy your major (as I do), it won't seem like so much work because the material will be fascinating."
Good luck!