Keep your door open.
Ask your roommate/floormates to go check out your buildings a couple days beforehand. You get to explore campus + find your room + find out just how fast you'll need to move between classes
Don't wear the DIS backpack + the lanyard around your neck
Join a learning community if your major/area has one. You get blocks of classes reserved for you to register in, get automatic study groups, and an upperclassman who can tell you what's going on.
Go to clubfest. Go to the first meetings for several clubs-including something related to your major, something you already know you like, and something that just sounds crazy fun. You'll get plenty of food from going to these meetings! I cannot stress how important joining clubs (especially major-related) can be. Most of my best friends came from that, plus my internships, current job, and countless networking opportunities.
And on that note, don't just join and leave it at that. Join a committee. Run for office. Yes, even if you are just a freshman.
Buy your books from half.com or a similar site. Don't buy from the bookstores. You probably won't even need most of the books- I don't think I bought a book junior or senior year.
Tell us your classes - we can probably tell you whether or not you need those books
Don't skip class, unless it's for an event your are working with. And if you do, email the professors BEFOREHAND, and ask what will be covered. If they are nice, this will save your *** in case of surprise quizzes.
Talk to your professors if you have questions. They'll have office hours. Use them.
Meet with your advisor more often than just picking up your code to register for class. Seriously. Mine got me my job (he was also club advisor for my club, see, this club thing is important! They can write recommendation letters for you!)
Study or do homework at least a little bit every night. Save yourself the pain!
Apply for every scholarship you can get your hands on
Don't go home every weekend
Go out and have fun, but be smart about drinking, drugs, and sex. Don't be pressured into anything you aren't comfortable with.
I would actually recommend not getting a job your first semester, unless you have a really easy class load. It can be very difficult for a lot of kids to start relying on themselves to kick them into gear vs. parents/teachers. Figure out how to balance your studying/classwork/social life first semester, and then get a job.
Study abroad or do a travel course at some point. It will easily be one of the best experiences of your life. (Actually just attended a wedding for two friends who met on a travel course)
Don't forget to call your parents every now and then
That's super-long, but a lot of it is stuff I wish I had done (or did do and was hugely helpful) when I was there!
Yes, most of us non-students are jealous of you kids moving in this week - it's an exciting and fun time!