When it comes to textbooks, anywhere aside from the bookstore will be a better deal. Amazon is where I go and they have a promotion going on where if you sign up using your school e-mail, then you get a trial of Amazon Prime with free 2-day shipping. I got it for two years, but mine's about to run out so I don't know what they're doing now. Be warned though, the bookstore will find a way to shaft you regardless. For instance, this past semester, my professor changed the order a couple months into the summer, but the bookstore didn't update the list so everyone in the class bought the wrong book. (Mind you, the textbook cost about $80 used from Amazon.) One class, literally half the books for the class were wrong, one was completely missing. It gets a bit ridiculous.
Some people don't buy books which I can understand for general education classes, but I know for me, the higher up you get, the more you want to keep the books for future reference. I plan on becoming a history teacher, so I save a lot of the textbooks from my history and education classes to use as reference later on.
The best advice I can give you in general: go to class. Simple as that, but believe you me, it's very tempting to skip in college, especially that one class at 8 in the morning that you hate with every fiber of your being. Aside from that, try to get to know people; you're experience will be dramatically shaped by them and it's having that close group of friends that will make your time there amazing.