In addition, how to learn mathematics and geometry well is a very empty topic. I can only tell you: 1, you can do more problems and accumulate experience. Of course. If you have time, you should also look at the topics you have done.
2. If you don't like the sea, my method is this: to do some classic examples, you should look at the process of solving the problem repeatedly, think about why you should do it, and look at it again and again.
I hope I can help you.