By default MiliPro theme will place Main navigation menu in primary menu region.
How To Add or Remove or Disable menu Links
Navigate to:
Home Administration Structure Menus Main navigation
example.com/admin/structure/menu
Here you can manage links of main menu.
How to make Drop Down menu
MiliPro theme has inbuilt feature of Drop Down menu powered by CSS3. It do not require any third party module for drop down menu.
Navigate to:
Home Administration Structure Menus Main navigation
Click Edit button of parent menu link.
Check Show as expanded option of this parent menu link and save.