Why can't I see the menu in the header or footer?

Menus with links to unpublished pages will automatically hide the menu item until it is published

If you have set up a menu that has unpublished pages, those links will be hidden.

To see your menu while building pages, set the menu item to "No Link" so you can see what the menu structure will look like, then go back and add the page links to the menu once the pages are ready to publish.