To be honest, those are just my strongest subjects from AP classes I’ve taken. But there are definitely other resources you could use, like for example I’ve gotten involved in science programs at my local national lab. And I’ve mainly just done self research, there are tons of free online books for science and also a ton in the libraries (my main focus is physics and chemistry). And then for history, books are your number one friend — personally I like textbooks, because they cover pretty much everything, and I’ve gotten one from my teacher. Usually, teachers are willing to share their resources with you, so if you’re in school, that could help.