Make no mistake. The purpose of a college class is to advance your learning in that course. The ideas that are presented, explained, and developed are often not duplicated in the text. When you learn what you should in class, your study time can then focus on the outside readings and exercises instead of on the material you should have already mastered in class. You may want to examine the following sets of behaviors, which characterize successful students.
Preparation begins the day before class.
If so, do them. More about this later. Become familiar with the main topics and new vocabulary and at least look at charts and graphs. Be sure to quickly skim chapter summaries. You may have to do serious surgery on your social life to accomplish such a goal, but the rewards are equally serious.