However, the goal of physics is to describe the maximum number of things going on in our universe in terms of the minimum number of general principles. Furthermore, these principles should be as simple as possible. In most physics courses, the primary source of your information is the textbook. The instructor is there to put the textbook material into perspective by amplifying, clarifying, demonstrating, and illustrating the ideas in the text. Your time in class will be spent best if you already have become moderately familiar with the material of the lesson by reading the appropriate sections of the textbook beforehand.
Some students attempt to write down everything the instructor says or writes on the chalkboard.
But I would like to suggest that sometimes you just stop taking notes, watch, and listen, especially if the concepts are covered in the textbook. If the instructor is explaining a complicated figure, doing a demonstration, or otherwise carrying out something hard to capture in notes, just try to absorb it as it is taking place. In this situation, the chances are your notes won't make any sense when you get home anyway, and the textbook will probably refresh you on what was done. Knowing when to take notes and when just to look and listen is something you'll have to learn from experience with each instructor. Your before-class study will help immensely with this problem.