Home is constructed with two Elementor templates:
agenda-sidebar and home-sidebar. Both put on the homepage as a shortcode. In agenda-sidebar is another shortcode named Agenda.

The actual content of Agenda and Home is in the template agenda-sidebar or agenda and home-sidebar. 

How to update

Home
Go to Elementor -> Editor -> Templates -> home-sidebar -> edit with elementor or

Agenda
Go to Elementor -> Editor -> Templates -> agenda-sidebar or agenda -> edit with elementor or 

Homepage Image
Go to the homepage under pages to change the image.