If you follow this documentation step by step, import demo data and select menu location, you are going to see the demo menu in your site.
Now follow the instruction bellow for adding you own menu to the Primary Menu location in the header. It’s same process like other themes.
Navigate to Appearance > Menus. Here you will see a link for create a new menu. Click on that link and give a name of your menu and save the menu.
Now add you menu items. This theme support one page navigation menu and multi level dropdown menu. After adding menu item save the menu.
Now go to the menu locations tab.
Here you can see the menu locations that this theme comes with. The Primary Menu is going to show in the header. From the menu selection dropdown, select the menu that you created few minutes before. That’s it.
If you want to change the padding of the menu, then go to customizer option.