Navigation/Menu Setup
Primary Menu
It's for the Multi-Page Site which will be displayed as main menu. To set the menu do the following
Creating & Setting a Menu
- Go to Appearance → Menus
- Click on Create a new menu
- Add some menu items to the menu
- Click on the Theme Locations tab select which menu you want to display in each area.
- There is a more in depth guide for creating menus on the official WordPress website here
Menu Image
- Add Featured image for page & post.
- Custom menu item & Category item.

Go to Appearance => Menus. Click on Screen Options & mark Title Attribute

Upload an image on Media and add that image url to Title Attribute