When you enter emacs, you are in a workspace. A cursor marks the position in the file, you don't have to do anything special before you start typing.
Just above the bottom of the screen, emacs prints information about what it is doing. This line is called the 'mode line' and may look like this:
--**-Emacs: myfile (Text Fill)---5%----
At the left edge of the mode line, you may see two asterisks (**). This means that whatever you're editing has been modified since the last time you saved it. If you haven't made any changes, the asterisks won't be there. Next, emacs prints 'Emacs:' followed by the name of the buffer or file you are editing (myfile in our example). In parentheses following this emacs shows the major (Text mode) and minor modes (Fill mode). Following this emacs prints where you are in the buffer or file (5%). If the entire file is visible on the screen, emacs prints the word ALL.