Hello Eugene Eng,
Thank you so much for using our theme SuperMagPro. As per your questions, please follow the below steps to show Home Main Content Area
1. Create a page. Example: Home
2. Create another page. Example: Blog
3. Go to Settings > Reading > Choose on A Static Page
4. Select the Home page for front page and blog for blog page.
5. Go to Appearance > Customize > Widget and you will get the home main content area there.(Refresh your site if not appeared)
Hope this will solve your issue. Please follow the theme documentation for better solutions.