Man, where to start? I'm jealous. You're coming up on the best years of your life. I won't turn this into a thesis, but will just throw a few things out there.
Use your time well. Study hard and efficiently so that when it's time to play you can break away and have some fun. You're there to learn and paying a pretty penny to do it, so the school work has to come first, but it doesn't have to consume your life if you do it well.
MAKE AS MANY FRIENDS AS YOU CAN. The more you have, the more options you'll have as far as things to do, people to study with, people to live with after freshman year etc. You'll never have an opportunity to make more friends (some of which will be life-long friends) than you will these next few years.
Be active. Play intermurals, join a club or two, go to athletic events. Don't sit around your dorm room and play video games all the time. Your college experience will be better if you make the most of it.
Lastly, keep your chin up. You'll have some rough days when a test or paper has you worried, but if you work hard it will all work out in the end. Things are never as bad as they seem.
Like I said, enjoy this time. I look back at my days at ISU as some of the best I've ever had. It's a special place.