The Polygon Documentation (free version)
Navigation (Menu) Bar
Now that you have tweaked your pages, it’s time to learn how to make your pages show a navigation bar.
You will be able to choose and arrange your Pages on the Navigation Bar via the Menus page. First, go to your WP-Admin left sidebar, click on Appearance and then on Menus.
Enter a name for your new menu and click on the button Create menu.
2. Choose the pagesBack to top
Next, choose the Pages that have to be shown in your Menu.
To do this, you will find a list of Pages on the left. Click on the Pages that you want to show in your Menu.
**Note - Sometimes only “Most Recent” pages are shown. To show all your pages, click “View All”.
Click on the pages you want to show, then click Add to Menu, and the pages will appear on your menu like the above example.
Concerning One Page, the calls of a menu are not pages in themselves, but calls created by the tab link of the menu. The single call of the menu has to be built as follows: '#id_anchor' with id_anchor equal to the one added through the shortcode 'One Page Anchor' in the specific spot of the One Page.
Now, add your Menu to your Navigation bar. In the above example, click on "Manage Locations" tab on the top of the page. In this section you cna find several custom menus to choose from, but we want to use “Menu”. So we clicked on “Main Navigation” to open a drop-down box, then on “Main Menu” for the Main Navigation.
5. CSS ClassesBack to top
Use "CSS Classes" option to change the layout of the menu entries.
Frontend HTML result
**Note: Click and drag the pages on the right side of your Menu to arrange them in the order you prefer.
SAVE ALL YOUR CHANGES!
For a more detailed explanation about how to set up your menu in WordPress, go to: https://codex.wordpress.org/Appearance_Menus_SubPanel.