The best guide is built in to Vim but sadly often overlooked.
Here's the reference manual: https://vimhelp.org/#reference_toc (`:h reference_toc`)
There's also a cheatsheet: https://vimhelp.org/quickref.txt.html (`:h quickref`)
Incidentally, the same advice apply to Bash: just read the man page, and search into it each time it is needed. It is just worth it.
1. It's way too long, the complete stuff is ten of thousand of lines. 2. It goes into needless details, especially at the beginning (the "finding help" section is intense for example). It turns me off each time. 3. It's too dry, not really enjoyable to read to me.