@scarletkrystal learning Racket, as in "I've already learned some Scheme (or Lisp) and now I want to learn what Racket brings to the table",
or learning Racket as in "learning some Scheme -- specifically Racket"?

If it's the second, I'd suggest SICP -- https://mitpress.mit.edu/sicp/

Which to use Racket to work with it, put #lang sicp at the top of the file. (info: https://docs.racket-lang.org/sicp-manual/index.html )