Reordering the Navigation Menu

How to Reorder Pages on the Menu Bar

Log into WordPress. If you are unsure of how to do this, view Logging in to WordPress.
Access Menus. Go into Appearance and then click on the Menu tab.
Create a Menu. Under the Menu Name heading enter what you want your main menu to be called. Click “create menu.” You can create menu items from any page, post, or category that you have saved from the box on the left hand side. You can also create your own custom menu links. Click on any items that you want to be included in your menu. Click “Add to menu.”
Rearrange the order that the pages appear by dragging the menu items up and down in the box on the right. Click “Save menu.”
Publish a Menu. In the Theme Locations box in the top left corner choose your new menu as your primary menu from the drop-down. Click “Save.”

More details about building WordPress menus.

Your menu will be updated and you can go to the visit site tab to see how your site looks to visitors. Note: Different themes support different numbers of menus and menu items, some only allow for one menu.