Theme extends standard functions for WordPress menu and makes it more flexible and powerful. In order to create menu you need to go Appearance->Menus and click create a new menu. After that add new items to the menu as you usually do it with wordpress and click "Save". You will see new fields editing menu item like Design, Icon name, mouse event and image.
You can choose one of three possible variants for the menu item dropdown style:
- Default - simple dropdown column
- Full Width - full window width dropdown
- Set sizes - set your own width and height for the dropdown
After add all the necessary items to the menu you need to set it as a main navigation for your site in Appearance->Menus->Manage Locations
If you want to add widgets or shortcodes (posts, products, images etc.) you can create HTML Block and put it's shortcode to the Description field.