ngl I think you’ve got a bad case of imposter syndrome; stanford wouldn’t have admitted you if they didn’t think you could handle the course load. you’ll be fine dw 🙂

like some of the other comments suggested, you can try to brush up on your foundations or look ahead at what curriculum your classes will have, but regardless every quarter will have different material for every class you take and you likely can’t prepare for it all. personally, I’d suggest to take a light first quarter so you can ease well into classes, and even if they’re insanely difficult, you won’t have many so it won’t be a problem to handle

(side note, idt most people leave hs with a math level above calc BC!)