This theme has two types of menus, the menu left and right menu.
By selecting the Appearance > Menus option from the WordPress admin sidebar, you can set the top navigation by creating a menu, and on the left under Theme Locations set the Main Menu dropdown to be your newly created menu and then click save. This will allocate your created menu to the header navigation of the theme.
Apper is used two menus named as top menu and secondary menu. The menus is have their own style as you see in the demo. Just create your custom or page menu and decide where you want place it.
1. In the settings menu, if you choose the "header menu", then the menu display you will be positioned on the left (default).
2. if you choose the "right menu", the menu display you will be positioned on the right.
The theme supports two levels of drop-down, so you can manage your menu items and allow for deeper navigation.