The "Events Template" Template allows users to filter between events and view either  a list of all events or a full calendar of events.  By default, this template doesn't support header images.

To add new content to any of these sections, navigate to Content > Events. Create Your Event, and assign it to the category you wish it to display in.

Detailed event help can be found at http://help.monkcms.com/article/events-overview/