Templates in Teams Manager are accessible in several spots depending on your role within the organization.
If you're an Admin, you can navigate to Settings > Templates within Teams Manager to view all Active and Inactive Templates.
As a regular user, you can view available Templates by clicking Create in the Teams tab within Teams Manager, but you won't have the option to actually edit or modify them in any way.
Each Template creates a corresponding team, which can be found under the Chat tab in Microsoft Teams; however, editing these in any way after the Template has been created doesn't affect the final Template.