You will need to add all your companies relevant locations for new employees to be able to select from when they are filling out their onboarding online forms.
Add a new location by selecting the blue 'Add' button, naming the location, and ticking 'Active'
When you leave 'Active' unticked it will then archive this Location - which you can then tick 'Show Archived' and click on the location and tick 'Active' in the archived locations to make that location active again.