The free theme contains homepage slider, services and welcome section.
To set the homepage slider
Go to Appearance -> Customize -> Slider Settings
Create the page for slider from WordPress dashboard
Slider Title manage from page title
Slider image manage from page featured image (use image size 1400px/600px)
Then select the pages from dropdown for slider
Please send your website URL and WordPress admin login details at email@example.com so we can check and setup the BizGrowth free theme on your website.
You can also check the documentation to setup the BizGrowth free theme