What major/ classes would i need to take?

humanities, foreign language, more english, etc?

up to what degree is required to teach a foreign language?
(Southern California)

i'm thinking of the highschool/ college level
teaching Japanese, or becoming an ESL teacher for foreign
(Japanese, Spanish, and Korean) students

personal experience/ good information please!!!

To teach college, you need to major in the language. You usually need a Master's to teach community college and a PhD for university teaching.

To teach high school, you need to get your degree in secondary education with a focus on the language you want to teach.

In some places, you can teach ESL to adults with just an undergrad degree (in education, linguistics, etc). However, most of those jobs don't pay very well. If you are serious about teaching ESL, get your MA in TESOL - then you can teach community college and at some other better programs.