The Agencies page is provided with a sidebar placed on the left side of the web page. A sidebar in WordPress refers to a widget-ready area used by the website to display information that is not part of the main content but is displayed in a vertical column. An example of Agencies page with sidebar can be found at this page.
How to manage the Agency Sidebar
In your left sidebar navigate to Appearance > Widgets and locate the Agency Sidebar box as displayed in the image below.
As you will notice, there are Available Widgets displayed in the left part of the page. On the right side you can find the Agency Sidebar where you will need to drag and drop the widgets that you want to display in the Agencies page.