Your site’s menu will appear at the top of every page, below the site header. When a page is added to the menu, you can choose to have it appear at the top level in the menu bar, or you can have the page appear in a sub-menu off of the main menu. Either way, you can easily rearrange items in the menu or add new pages to the menu.
Log in to your site
Click Menu in the administration bar at the top of the window
Click Main Menu in the sub-menu of the administration bar
Use the four-headed arrow button to drag the menu item to its new location
To make a page a sub-page, drag the four-headed arrow to the right
When you are done rearranging the menu items, click Save