Prepare well before class, listen in class and do homework after class. Try to do exercises in the textbook by reading definitions, properties, formulas and examples before class. Find out what you don't understand and come to class with questions. Listen carefully in class and take notes in a way that suits you. I still remember the teacher's interpretation of the definition and the problems in the teacher's preview. Of course, don't delay class because of taking notes! At the same time, boldly put forward what you don't understand to the teacher. Finish your homework carefully and independently after class. If not, go back to the textbook! Read! Read! Homework is the feedback of what you have learned in class. I can't do it, which means I haven't understood it yet. If you really can't, then ask the teacher (or someone else) for help and figure out the problem! Be careful not to ask others easily without thinking.