The library does not have most textbooks. Sometimes a professor will put textbooks "on reserve" at one of the campus libraries, allowing the books to be checked out for a few hours or a few days. But unless you are looking for something such as a novel or play to read for class, we probably don't have your textbook. You are certainly welcome to search our catalog to be sure!
You can also try requesting a textbook we don't have via Interlibrary Loan, but again, few libraries collect textbooks, so you may not be able to get it that way either.