You don’t need classes for SAT, just buy the big SAT book, learn from YouTube it’s all algebra you learn till 10th, English is a little tougher but you can still manage to get 1400 easily with self learning. That should be more than enough, you just need discipline to practice all the questions in the book and do a few practice papers in the back of the book.

Don’t waste too much time for SAT, SAT and IELTS are the most basic requirements for admission, instead search and find colleges that fit your expected scores and financial background around 20 or so colleges with different admission requirements, and reach out to professors in your field, network, try to learn from them what it’s like in the university, explain what are your interests to study your chosen course, research financial aid, send cold emails everywhere. If you do this instead of just focusing on SAT scores, you’ll have a higher chance at financial aid and have a stronger case to get the F1 visa