First, follow the teacher first and preview before class, so that you can follow the teacher and it is not easy to break your mind. Once your brain is broken in class, the basic course will be abolished.
Second, you must make up the previous foundation. Don't be bored. There are many high school courses that are related. You don't understand a knowledge point. You may need it next semester. Take out the math book of Grade One, and you can buy a reference book (Rainbow Houxiong). The principle is explained in detail in the reference book, and you can't buy questions as soon as you come up. If you don't understand the principle, it's no use buying questions.
After understanding the principle, do the problem to consolidate. The purpose of doing the problem is to deepen your understanding and memory of the knowledge points.