This is a very tough question to answer. I know some people will be like "you're too young to wear makeup!" or other things, but I think it depends on you and your skin type. If you're not experiencing any problems like acne or discolaration, I wouldn't go into wearing makeup. But I actually know some make-up gurus on youtube who are very young, around 12-13 who are wearing makeup and giving advice, and that's okay too. If you want to wear makeup for fun or just on an occasion, then that's fine. I would start out light. Once you're 15-16 and entering high school, I think that's an appropriate time to start wearing makeup more often.
If I were you, I would just wear sunscreen or like a tinted sunscreen. But seriously, if your skin is okay, then don't wear makeup! Natural Beauty is the best