Welcome to JavaRanch
I shall give you conflicting advice. Take it easy. Chill out. Cool it. Leave off programming until you start your classes. If your teachers are any good, they will be better able to teach you programming than you can learn from a book. In fact, when I started my course, we were advised not to buy any books before the course started.
Go to your library and read around the subject. Look at books like "Code Complete" by S McConnell which is about the software development process. Read it until you get bored, then take it back and find another book.