Create a new, empty page (e.g. with the title of Home or Front Page), enter the title(1) text and the short text(2) of the main content, and upload Featured Image(3).
Press Publish button. Now you can go to Appearance > Customize > Static Front Page and choose your new created Page as your Front Page.
If you want to show your Blog (Posts Page) you will need to create another new, empty page and call it Blog or News. Now you can choose your new page as your Posts Page under Appearance > Customize > Static Front Page.
Then you can to settings of the front page sections. Go to Customize > Front Page Sections. You can customize the look of the main content of the front page in the section Appearance > Customize > Front Page Sections > Page Content.
If you want to use the Callout section on the front page, you can configure it Appearance > Customize > Front Page Sections > Callout / CTA. There you can also customize the Widget area: Front Page Sections > Widgets Area Columns.
Next you can customize visibility and order of sections front page: Appearance > Customize > Front Page Order.