The first question I'd ask is, what kind of language do you want to create?
That makes it a lot easier to answer a question like "Is X a good choice for Y?" It depends on Y! :-)
Then, along with asking here (which is fine), you might also want to ask the Racket folks. Go to https://racket-lang.org/ and scroll down to "Community". Then you can ask, "I'd like to create a language like Y, would Racket be a good choice? If so, how would I go about it?"