If you just want to learn math well in junior and senior high schools, it is still relatively easy, because the content is not too much. I provide a stupid method for reference: recite all concepts, all theorems and all theorem proofs. It is best to be able to prove it by yourself without reading textbooks, and then be familiar with (preferably recite) all the examples and their solutions, and do exercises after class. You'd better take the initiative to contact them when you do the problem.

Of course, learning by yourself at first may be a headache to recite. Try to copy the textbook several times to deepen your memory and help you recite. Of course, after a long time, it is not necessary to copy.

To tell the truth, it takes effort to learn any course. The above method seems stupid to death, but it is very real. If we can persist in it for a long time and extend it to the study of other subjects, it will certainly have unexpected effects. Didn't Guo Jing make some stupid efforts when he practiced the eighteen palms of the dragon?