5. Theme Options
The theme uses the WordPress Customizer feature for it's global/theme options. Customizer is a native WordPress feature which was added in WordPress back in 2012, so if you've ever used WordPress you won't have any problems.
You can access the customizer at WP Admin → Appearance → Customize. In there you will see these sections:
The sections Home, Footer and Styling are custom sections the theme adds.
In the Home section you will see subsections where you can manage the homepage content ( more on that in the Homepage section of the documentation ), in the Footer section you can manage the footer subscribe and social areas and in the Styling section you can change colors/fonts.
To change the logo ( either change the text or set an image ) you can do so in Site Idenity.