The Primary menu is either located on the right of your header. The menu font and style can be edited on your theme options >> menu settings page. This menu disappears for mobile and is meant to be replaced by setting up a Mobile Menu.
The topbar menu is located in the topbar on the left side. This menu doesn’t not change for mobile devices so use caution when adding a lot of items to this menu.
The footer menu is located in the bottom right corner of your site. It is not designed to be used with submenus.