Emacs actually comes with an in-built tutorial. You should already have an emacs session up and running. In the emacs window, type Ctrl-h t
This should start up a tutorial session in your emacs window, probably starting with pre-amble at the top of the page
Copyright (c) 1985 Free Software Foundation, Inc; See end for conditions. You are looking at the Emacs tutorial.
What you should do now is work through this tutorial, doing all of the exercises along the way. When you are done, go on to the next section.