Emart has 4 header styles.
Overview
Header v1
Header v2
Header v3
Header v4
Logo
You can set header Logo for individual pages via Elementor.
Here you can change your logo by changing the image.
Primary Navigation
Output
Settings
You can create a menu for your website from Appearance > Menus.
Once you’ve create a menu, you can assign the created menu using MAS Nav menu widget. Also you can style your menu via style tab.