Hello @nejobest,
Thank you very much for the appreciation .
The section you have marked is the home content . So now to display as in the demo you have to place your desired content in the content area of home page edit screen and as the image comes from featured image section you have to upload the image of your choice in featured image section .
Here home page is refereed to as the page that you have assigned for Front page by going to Admin panel > Appearance > Customize > Static Front Page .
Screen shot :
https://image.prntscr.com/image/iXyTxvUiR9WLWvPzgTG5wQ.png
Also make sure you have enabled the Home page content by going Admin Panel > Appearance > Customize > Theme Options > Home Page Options .
Hope this helps .
Let us know if you have any confusion further .
Best Regards!!