Common emacs commands

emacs gets you in.  You can also say emacs myfile to load a file when you start.

In what you see below...

Meta-x means hit Esc then hit x

Ctrl-x means hold Ctrl down and hit x.

Basic commands
Ctrl-x Ctrl-f load a file (or make one)
Ctrl-x s save a file
Ctrl-x 2 get 2 windows
Ctrl-x o go to other window
Meta-x shell get a command prompt
Ctrl-x Ctrl-c close emacs
Ctrl-g abort current command
Meta-x goto-line goto line (by number)
   
Cutting and pasting
Ctrl-k kill (cut) current line, to end of line
subsequent calls kill subsequent lines
Ctrl-y yank what you just killed (cut) back,
at current cursor location
Ctrl-<space> start a region to cut
Ctrl-w cut it

Tabbing on a particular line indents it appropriately based on the mode you're in.  If your file ends in .lisp, you'll be in LISP mode.