All Zones belong to a Zone Category. They help us, well, categorize our zones. You will see each Zone's category under the Name and Positioning panel of your Zone Tool Settings.
These Zone Categories can be created/edited/deleted via Options>Attributes>Zone Categories, but I would strongly suggest not doing that if you're just starting out. Best to leave any attributes alone for now.
Instead, right click on your schedule in the Navigator or Organizer and select 'Scheme Settings'. Under the Fields panel, you will see 'Schedule Fields' on the right hand side. Select 'Zone Category' from the list and hit the Remove button.
Hope that's what you were after. If not let us know. And please include a screenshot.
Cheers,
Link.