I have your version.

You are in your document.
Click on VIEW
then on HEADER AND FOOTER

Now a small dotted box appears at the top of the document, and a header / footer menu also appears. My cursor is flashing IN THAT SMALL DOTTED BOX.

Just type what you want in that box!

On the menu bar that pops up, I have never used the "Insert Auto Text"

The next item on that menu is the icon to insert the page numbers

Next icon looks like a double plus sign. That is total number of pages. Use it if you want to put: Page 1 of 16, that icon does the 16 for you.

Next icon is to format the page number and so on.

I have Word set to show labels when I put the cursor over an icon, so I can figure out which one I want.

Hope this helps!
Sandie