Yeah, especially for freshman, youll have a good week before hw is assigned is most classes. Be careful though, there are 3 main bookstores on campus, TIS, Illini Union Bookstore, and Follett's and they can run out very quickly. It could be a few weeks before they get new textbooks in, so don't wait too long, ask the professor after the first lecture you have.
Worse comes to worse, there are book trading sites where you just meet with people in person and buy their used books for cheap, but its all handled by the people involved, kind of unofficial. Illini Book Exchange