I always recommend Harry Potter to anyone who wants to start reading in English. The first 3 books are more or less Middle Grade whereas the later ones are in the YA (young adult) category. Unless you’re very comfortable reading adult books, I’d always say start with at least YA if not Middle Grade. I don’t personally recommend classics unless it’s really your thing. They tend to be slower reads with more dated expressions and writing styles. If you really want to read classics, I personally like the Picture of Dorian Gray and Rebecca.