Common Lisp is awesome. SBCL is fast, there are a lot of decent libraries (https://awesome-cl.com/), and you can use it immediately in production. Lisp REPL-centric development requires some adjustment, and basically* you don't have other IDE options besides Emacs with Slime or Sly, but Common Lisp was the reason I finally learned how to live with Emacs.
* — there are also Slyblime for Sublime Text and ALIVE for VS Code, but they are very beta-quality.
For someone who's never used Emacs properly, what's a good tutorial for using Emacs together with CL in the synergizing ways that people claim are so amazing?
He doesn't take you by the hand to setup an environment, but it's a neat exposure (introduction isn't quite the right word) to someone using CL to do interesting things.
Mind its a bit Mac and Clozure CL specific if you wanted to follow along, but it's still a good watch of just seeing someone doing stuff without explicitly telling you what they're doing. Sometimes you just want to get stuff through osmosis, and he does interesting, basic things with CL at all sorts of levels.
Maybe start with https://lispcookbook.github.io/cl-cookbook/emacs-ide.html The 'magic' though isn't really that emacs dependent; if you like vim (like I do) you can use vim and still get that amazing experience. https://lispcookbook.github.io/cl-cookbook/editor-support.ht... has some details on alternatives. Anyway, the magic or synergy is really a combination of: CL itself being designed to support interactive development, a little server you embed (typically automatically if starting from an editor) in a running CL program called Swank, and a standard set of commands to talk to that server (and the underlying Lisp) and interface with your editor called SLIME (https://slime.common-lisp.dev/doc/html/).
The basics of the commands do things like send code over for compilation and redefining things, running things, responding to errors, debugging things, jumping to definition locations.. things you'd normally expect an IDE to do, except because of CL itself so much of that is part of the language and not a separate IDE. Some more editor-specific things come into play that some people really love, and while they may be best done in emacs they're not unique to emacs either. (Example: suppose you messed up the order of your arguments to a function, so it's written like (my-func (list something) some-other-arg) -- editors have support to swap those two arguments in one go, rather than having to backspace and retype or whatever. I personally don't find such features that magical, and are table-stakes even for things like Eclipse editing Java. Meanwhile even emacs is still weak for some things like large-scale automated semantics-aware refactoring...)
* — there are also Slyblime for Sublime Text and ALIVE for VS Code, but they are very beta-quality.