Racket is a great choice for learning but also very batteries included if you want to make real projects in it.

Janet has a more Clojure-inspired syntax but the semantics and general ideas should carry over. I think trying to work through the books in Janet would be a great extra challenge. You can always drop that and focus on Racket if it becomes it too much for you.

Why not try doing the exercises in Janet? It gives you the end-product goal so you don't have to waste energy on ideation, but having to figure out syntactic differences and compatible standard library functions and macros yourself really helps you understand a language top-to-bottom and is arguably the best way to learn. The way I learn languages all the time is to translate exercises on sites like HackerRank or exercism along with toy projects I already have.

I haven't used Janet but there were some notes in the author's ebook (https://janet.guide/) that suggested it had some small but key differences with a more "traditional" Lisp that might trip you up or at least cause friction. I'd suggest using Racket for those books.

With a little bit of effort you can make it work. But I believe Racket has specific language definitions for some of these books so you can follow them more or less seamlessly.

dont overwhelm yourself. use the language the book was designed for

common lisp also has some really great books, beginner and advanced. paip is probably the most famous of these

Are you familiar with Lua? How about Fennel?

because Janet is a lisp-1, this should be very doable.