If you need page numbers—and only page numbers—without any further header or footer information, there's a great shortcut: the Page Numbers command on the Insert menu.
Inserting page numbers this way is very simple and quick. You can choose whether you want the page numbers at the head or the foot of the page in the Page Numbers dialog box. You'll get to practice this in a moment.
If you later decide that you do want more information in your headers and footers, this is okay. Open the header and footer areas normally and you'll see that the page numbers are already in there.