When I was in high school, I took advanced mathematics courses offered by my school. In the first class, the teacher stressed that I should spare no effort to take this course again, and don't take up my time studying the normal teaching content in high school. Otherwise, I think I have been exposed to mathematics from a "high viewpoint", but my vision is superior, my foundation is not solid, and I can't learn anything well in class.
There are also many students who started to learn advanced mathematics very early and then dabbled in many frontier fields of mathematics before entering the university. But the reality is that even such a student, you have to have relatively excellent in-class results as a passport to enter colleges and universities (or you have achieved quite excellent results as a student in a math competition, but the knowledge used in math competitions in junior and senior high schools has almost no intersection with advanced mathematics).
My suggestion is that if you don't do well in math, don't try it easily (at least don't take up too much time). If the subject is among the best, I don't think it's harmful for you to get in touch with this much deeper and wider mathematical world than junior high school. However, if you are not interested in mathematics research in the future, I still don't recommend that you spend too much time, because it is likely to affect your enthusiasm for learning other subjects (when you are curious and enthusiastic about this unknown field, you will unconsciously invest a lot of time in it).
The above personal humble opinions are for reference only.