My school doesn’t offer any APs for freshmen, only 3 APs for sophomores, but around 15 for juniors and seniors. I don’t really want to overload my junior and senior year with ALL APs, but I don’t want to take too little either.
Take AP classes on subjects that you enjoy. If you’re a STEM person, take physics, chemistry, Calculus, etc, and dong bother with things like psychology, euro history, etc. If you’re a humanities person, take English, history, psychology, etc.
If does not matter the quantity of AP’s, just that you are dedicated and interested in the ones you do take.
I agree that there is no magic number, but you’ll be able to find what works for you. Don’t worry! Through reading your reply to my thread (thank you by the way) 
I’ve found that we are quite similar! My advice to you is to first eliminate the classes you have no interest in, because honestly there’s no use putting yourself through that. For me, that was AP history, so I know I won’t be taking any of those throughout high school. Next, consider your EC’s. It sounds like you have a few great ones, and it would be more valuable to pursure those than to overload yourself with AP’s. If you really have no idea how many AP’s you can handle, consider taking all the ones you have interest in and dropping as many as you’d like once you get a feel for them. I’m taking AP Psychology as a sophomore who loves science, and it is super interesting. As a starting point, I would highly encourage you to leave at least one class regular (not honors or AP) because honors can sometimes be just as hard. Currently, I’m taking 2 AP’s, 3 honors, and one regular and it’s working out pretty well for me. Feel free to let me know which ones your considering and why they interest you, or anything else. I’d be happy to give more advice. Good luck!
Thank you, Shanban1607 and atlasgenius1 for replying. I love science (but I hate math… which doesn’t make much sense since science is 20% math, and physics is 90% math), so I am definitely planning on taking AP Biology, AP Chemistry, AP Environmental Science, and AP Physics 1 (our school doesn’t have AP Physics 2). The problem with taking College-Prep level classes (regular classes) is that I really do want to become valedictorian (or at least salutatorian). I believe that’s achievable for me, since my school is not competitive at all, and there are 320 students per class, but there are still high-achieving students at my school.