Athena Pro features 10 Widget areas, including a pop-up widget area over the Jumbotron (“Slide Overlay”), and four full-width widget areas on the homepage. You can populate these areas with text, shortcodes, images, or whatever you like.

To activate or disable these Widget areas, go to Appearance > Customize > Frontpage, and then click in to the Widget area you want to edit.

Homepage Widget Area A has a shaded background image in the background that you can edit from the Customizer. Go to Appearance > Customize > Front Page > Widget Area A.

You can change which active widgets are in the widget areas from two places:

From your WordPress Dashboard, under Appearance > Widgets;
From the Customizer under Appearance > Customize > Widgets.

To learn more about using widgets in general, check out the WordPress codex.