Choosing a theme in Pages will create a default Menu of your Pages website. To change the default Menu on your website navigate to the Menu settings.
In the above image click the Menu navigation in the Menu and then you can edit, delete and Add new link. To add new menu click the Add new link it will show you the three Item Types that you may choose for your Menu.
- Menu Heading
You may also indent the menus in the Primary Menu to make a sub-menu by dragging it to right and click Save for website name.