However, you can practice the SAT by yourself, just find some books.
Official Olympic organizing Committee
Monkey Brother's vocabulary (highly recommended, other vocabulary books are not so specific about SAT).
White (forget who wrote it) SAT grammar, reading, vocabulary
Barron's book can also be made.
There are also Princeton books that can be made (red and white books), but the problem is that they are hard to buy, and there are fewer exercises on them, which are also more expensive than OG.
Mathematics is too simple, just do it yourself, as long as hands are not born.
New Oriental does have classes, but I don't think it would be interesting if it weren't for Beijing New Oriental, because the teacher who taught you probably didn't teach SAT specifically. The grammar of SAT is quite different from that of normal English. If you follow normal English, the problem of pronouns alone can kill you.
Other cities may teach SAT specially (such as Su Xifu), but the quality of teaching is not clear, so we have to listen to several classes. But this has an advantage, that is, the time arrangement is more free, and even the lectures can be given remotely (or the VIP classes in New Oriental can be a little more free).