Note Suzanne's warning...
I don't quite understand what you're doing with font and page setup.
You can either use "Insert > Page number" (which I avoid since it inserts the page numbers in a frame, and that seems too complicated and not helpful), or "View > Header and footer", click in the footer (if you don't want the page number in the header anyway), and then click on the button with the page and a # in it on the "headers and footers" toolbar.
If you have successfully added page numbers to your template, new documents should have the page numbers.
Old documents aren't changed... You'd need to open them and add page numbers yourself.
If that doesn't help: What exactly "doesn't seem to work"?
Regards,
Klaus