For an International Student from India (AKA me), classes at IU were an amazing and radical departure from what I was used to. Though some of the distinctions may take a little getting used to at first, the feeling of pure, unadulterated academics being stuffed down your throat and in your brains in a new country with new people is a beautiful experience.
University students at IU are treated like adults, and are expected to behave the same way. Usually, if the class size is big enough, you can use your phones and/or laptops, leave whenever you want, and basically pretty much do whatever as long as you don't disrupt the class for the other students. For an Indian student, after having suffered under the tyranny of borderline totalitarian megalomaniac teachers in high school, particular difference was a godsend. More importantly however, its imparted a sense of accountability in me that I never had; I now go to classes, take notes and pay attention not because I'm being forced to, but because I want to (and, well, because I'm paying out several unmentionable orifices for it).
At IU, professors are more than just the noble vessels that impart knowledge and wisdom to us peasants; they are also an amazing resource. From Office Hours to E-mails, as long as you're polite and smart about it, professors are extremely patient and will go to great lengths to help individual students. Emphasis on polite and smart though; some get too comfortable with this advantage, and forget common courtesy, or start bothering professors because of stupid, inconsequential things. Do not be that guy, c'mon.
MAKING FRIENDS PAYS
The competitive spirit at IU is a purely positive one; everyone wants to see everyone else succeed (unless the grade's gonna be curved, in which case wear a bulletproof vest if you scored higher than a C in Finite). Be engaging, courteous and allowing towards your peers, and it will pay off. Moreover, the harder classes get, the more you're gonna need help, so invest in making friends early on. Of course, this does not mean engage in plagiarism or academic fraud; IU is serious about that stuff, so please, for the love of President McRobbie, do NOT cheat. You will get caught.
HAVING FUN MATTERS
The liberal faith put in students at IU leads to a lot of fun; you can choose to study whenever you want, and as long as you go to class and get your work done on time, no one will bother you. But make sure this fun doesn't turn into escapism, because things get sticky from there. DO NOT EVER MISS CLASS. I cannot stress this enough. Even if your class doesn't have an attendance requirement, go. You will regret it if you don't.
Above all, you don't want to let your freedom become the cause of a lot of stress and anxiety, so make sure you're productive every day; make sure you have fun completing your work, and then have even more fun doing actual fun things knowing you've completed your work (Too convoluted? Sorry, my bad). Above all, remember; Grades are temporary, but your GPA lasts forever!