When you go to  Customize, there you will see various options available to customize your site. Just try those options one by one you will be able to understand how the theme works and can create any kind of site.

Some Available options in Customizer:

• Site Identity
• General Settings
• Header Image
• Background Image
• Menus
• Widgets
• Homepage Settings
• HomePage Setting Options
• Theme Options
• Webmasters Tools
• Open Graph
• Twitter Summary Card
• Additional CSS