Wow, this is a huge topic! Emacs is a much-beloved text editor that does lots of things. You can even play an rpg (nethack) and talk to a robot psychologist inside emacs.
To start with, if you have a *nix system, you probably already have at least the command-line version of emacs installed, and maybe even a GUI version. The GUI version is very easy to use, it has a lot of menus where you can find the stuff you want to do and you can find out the keyboard shortcuts and stuff. The text version is a little harder.
Opening emacs:
You open it by typing emacs at the command line. This shows you the scratch buffer. From there, to open or create a file, typeCtrl-x Ctrl-f.
If you already know what file you want to edit, you can type emacs filename and it will show you the file straightaway. This also allows you to create a new file namedfilename.
To Be Continued. Dot. Dot. Dot.
- C-x means "Ctrl-x". C-x C-f means "press Ctrl-x Ctrl-f (without letting up on the control key)". C-x k means "press Ctrl-x, then just k".
- M-x means "Meta-x", which is usually "Alt-x", unless Alt is not mapped properly, in which case you should try "ESC, then x". And you should also try to find out how to map Alt to Meta.
- M-x compile means "Alt-x to get to the minibuffer, then type 'compile'"
- C-x C-s = save
- C-x C-c = quit
- C-c C-c = run Python program
- M-x compile = compile any program (but biased toward using make)