Your school or college board can provide braille acomodations. Get what you can of those. Also make sure to request for extra time on the sat I think I had like triple time.

Personally I didn't love my SAT experience. Very luckily though, the year I was applying to college was the COVID year and many places do not require it. Having said that, I'd recommend that whatever accommodation you chose, get familiar with it. If you choose a reader, if possible, prepare with them ahead. I found the grammar section with its inconsistent syntaxes and formats quite challenging for the reader. As for maths, you could actually contact CollegeBoard and have them send you a physical practice test. I got one and you can learn the graphs and geometry that way.

Hey, I haven't taken the SAT yet, but I've taken the PSAT. (I'm set to do the SAT in October). Khan Academy is a good resource for reading/writing and math. If it's possible and if you read braille, maybe connecting a braille device to a computer/phone would work to view math equations?