Emacs has great interactive tutorials built in: C-h t and has a great info system and help functions: C-h h also: https://www.gnu.org/software/emacs/tour/ http

Emacs has great interactive tutorials built in: C-h t and has a great info system and help functions: C-h h also: https://www.gnu.org/software/emacs/tour/ https://www.gnu.org/software/emacs/tour/ There is really a lot of excellent documentation built in and the source code is very easy to find and read.