A preview, preview first and then write down what you don't understand, and listen carefully in class.
Second, after class, we should carefully review the questions that the teacher explained in class and the questions that we didn't understand during the preview (the teacher should talk in class, and if the teacher doesn't talk, you can raise your hand and ask the teacher questions or ask the teacher after class).
Do more exercises, and you will be familiar once and for all. If you do more, you can basically master it.
Wish you success! ~