Moving this discussion to the Creating, Editing & Exporting PDFs Acrobat sub-forum.
Thank you for the help Jeff. That solved my problem. I'm still learning how to use this program.
In Adobe Acrobat you can use the Header & Footer tool to place page numbers on an existing document. It's on the Tools panel, Pages section.
You can change the start number from the automatic one by clicking the "Page number and date format" option on the Add Header & Footer dialog box.