Drawing Regions on Map
Note: This video is a bit old. It shows an older version of QGIS. With QGIS 3 some things may work differently, and some things you might be able to do without installing plugins.
Draw the borders of your congregation by adding a feature to the region layer. For the congregation boundaries you should select the congregation checkbox. To show all of the congregation area in the territory card minimap (top left corner), also select the minimap_viewport checkbox for the same feature. Otherwise draw one or more new features just for the minimap viewport. To split the congregation area into multiple named sub regions, you may create features with the subregion checkbox selected.