To configure the main menu, navigate to Appearance > Menus. First, give your menu a name, then build your menu by dragging pages from the left column into the menu structure. When you have built your menu structure, click create menu. After the menu is creating, towards the bottom of the page, check the field labeled as “Primary Menu”. Then click “Save Menu”.
As you build more pages, you will come back to this screen to add new pages to your menu.