Adding an internal page (one that exists under the “Pages” section) is easy. All you need to do is locate the title of the page, check the box (or multiple boxes, if adding multiple pages) and click “Add to Menu.”
Locating a page
If your site has many pages, you may need to search for the page title until you come across the correct one. To make this easier, WordPress supplies three different searching options:
Most Recent – This tab will display a list of pages you’ve most recently edited or created.
View All – This tab will display a list of pages sorted alphabetically. This section may have multiple pages, depending on the number of pages on your site.
Search – The search tab gives you a text field for specifying keywords to locate. This is often the quickest method. Note: The keyword needs to exist in the title of the page, not the body text.