The BizGrowth PRO theme is built in more user friendly Theme Options where as the BizGrowth lite version is in WordPress Customizer. You can use your previously created pages, posts, menus in customizing the PRO theme.
The PRO version contains lots of sections for creating beautiful and professional website.
Go to Appearance -> Themes and activate the BizGrowth PRO theme
To show the default home page with all sections as displayed in demo site http://gracethemes.com/demo/bizgrowth/
Go to Settings -> Reading -> Front page displays
Click on radio button of Your latest posts
Go to Appearance -> Theme Options and click on Restore Defaults in bottom side
Please see the documentation, it will surely help you to install and customize the theme.