First, read the textbook, first understand the concepts, theorems and formulas, and make these things clear.

Second, look at the textbook, how to solve problems with examples in the book, and learn the direction of solving problems with examples. In other words, if you encounter the same problem, how should you think about the direction of solving the problem, that is, which direction should you learn to achieve your goal? This is the most important thing, you must learn it. This is the basis of learning mathematics. The direction of learning to solve problems is that you have wisdom and learn concepts, but learning knowledge and wisdom is the most important thing.

Third, there are still some problems to be done, but they are not sea tactics. Learn to sum up, that is, which direction to consider when encountering such problems. What conditions does this question give? What formula do you want to use when you give these conditions? Generally speaking, conditions must be exhausted, but they will not be insufficient. This is a principle. It is ok to learn these when you do the problem. I wish you good grades.

If you want to use it, look at these "examination questions" and "golden papers", and personally recommend "golden papers".