When I try to delete an existing page, I see a message that says there are no pages to delete.

Certain pages, such as the home page and shopping cart pages, are required and therefore will not be available for removal. If you do not want someone to see one of the pages (such as the home page), you can remove that button from the other pages so the visitor will not have a way to navigate to that page. The key shopping pages, however are required for a successful order placement.