After installing theme, I recommend you to add some posts or products and widgets in Appearance – widgets.
Then, it’s time to make basic settings of theme. Go to theme option – general and choose Category and Blog layouts.
Then go to theme option – header and menu and choose your header layout.
Colors of theme, colors of menu, backgrounds, menu settings, you can add in theme option – appearance and theme option – header and menu options OR you can also use Customizer for this to live preview all changes. For this, open your site as administrator. Then, click on link in Admin bar
In theme option section you can configure Menu options and colors
In Site Identity you can assign logo and paddings in logo.