As others say, begin with the built in tutorial. It should be as simple opening Emacs and pressing enter. If for some reason it's not that simple, open Emacs and press Control+h followed by 't'. The tutorial walks you through the basics. The tutorial mentions C-h v. There is also C-h f for functions.
Next, when you're ready, learn Emacs Lisp. You can read An Introduction to Emacs Lisp online or within Emacs (using C-h i eintr).
Otherwise, hack and extend it. The joy of Emacs is that it presents you with programming problems at the threshold of your understanding. You decide whether to dip in. It provides you amazing resources to do it.
I hope you find a speedy recovery to your injury and have fun with Emacs.