I need tips on reading and vocabulary.

I think your best bet would be to read things that native speakers also consider high-level reading. Nothing too serious or difficult, but more enriching than your average novel or something. If you're looking to expand your vocabulary, I'd recommend reading scholarly/academic articles. Or you could read an educational book on a topic you're interested in. I know Google Scholar has a lot of free reading material, and even whole books. JSTOR also has some options that allow you free access to a limited number of books/articles.

Hi. How do you rate your English, now? Can you give me an idea, in terms of A1, A2, B1, B2, C1, C2? Or just describe it. It's very hard to tell from text. Knowing your current level will help me to give you the best advice. Second question is, do you *need* to pass SAT exams for some reason, or are you learning for personal development? I am asking that because, IMHO, studying the specific requirement of SATs is *only* useful if you need a certification. I noted your postscript. I will certainly offer advice, but answering those two questions will help me tailor it. (And yes, I'm deliberately using a few terms that I think you'll need to look up... I do that.) *edited for typo*

Well it depends what you like, but books by Terry Pratchett, Leslie Charteris, Raymond Chandler are all good choices. Almost anything written before 1900, for example the Sherlock Holmes books. And of course a lot of literature, Conrad, Nabokov, the names here are more obvious.

Higher levels of English is great for the sat, but make sure to check out other resources for it than getting your level of fluency up. Much of the SAT is very finnicky, you should try to study grammar and craft as well as English in general. I'm sure you already know much of this, though. I'd say book wise, reading classics such as Dickens and Shakespeare will help you wrap your head around more of the language, although it may not directly help you. The SAT is based around standard English conventions.

I am going to suggest a couple commonly read books in American English high schools that are not only good books but I think would be good for you. Of Mice and Men by John Steinbeck. Rita Hayworth and The Shawshank Redemption by Stephen King Catch 22 (very good for non common usage and slang) To Kill a Mockingbird