I found the ebook Mastering Emacs, and the accompanying blog to be extremely useful, even after going through both Spacemacs and Doom Emacs. I may go back to a modal workflow in the future, but for now I'm embracing Emacs' built-in ways of doing things, with a few exceptions.

http://www.masteringemacs.org

You may balk at the $50 pricing, but it gives the most complete picture of how Emacs works than anything else.