emacs is quite approachable because of its self documenting nature. In practice, if you want to drill down on a particular thing, you need to use some of the describe-* commands. For example want to know how emacs save something?

1) find the command it uses with describe-keybinding, you find the command "save-buffer"

2) "describe-command save-buffer" brings you onto the lisp world where it is defined => "files.el"

3) want to know how a variable is define within files.el? "describe-variable buffer-file-name" and now you are in C territory

4) rinse and repeat with some describe-function when needed

5) get lost onto the beauty of emacs which in my opinion is its interactive / self documenting nature which unfortunatly is not more common in all the software we use