Emacs is fine; Racket mode is very good [1]; but DrRacket is worth a spin if you're unfamiliar with the language/ideas.

[1] https://www.racket-mode.com/

I find Emacs with racket-mode much better for editing, but DrRacket has some really nifty IDE features that racket-mode doesn’t have. I probably split 80/20 between them

Racket's IDE is pretty good, but it doesn't match the pure editing facilities of Emacs, and racket-mode supplies similar functionality. I use exclusively Emacs for Racket, and other Scheme-like languages.

As the other commenters have mentioned, Racket Mode is excellent, especially racket-xp-mode: “An optional minor mode that enhances racket-mode to explain and explore code.” https://www.racket-mode.com/#racket_002dxp_002dmode

The other thing worth mentioning is Racketeers often use their favourite editor, only switching to DrRacket or Racket Mode when they need specific functionality.

DrRacket is a pretty good IDE but, it doesn't have the flexibility and consistency of Emacs. A lot learning material for Racket features the DrRacket IDE.

I find it easier to trace errors in DrRacket than racket-mode, but use Emacs for 95% of my Racket coding