This will most likely be because you do not have Booking Stages set up within your Settings. You can add these within either your Venue settings or the Venue Group settings if you have multiple venues and would like the same stages for all venues.
To do this, head to:
Venues (if setting at Venue Group, head to Venue Group at this point)
Select your Venue
Labels & Colours tab
Under Booking stages
There is the option at this point to either use ‘Example Booking Stages’ which will default to:
Alternatively, you can create your own Booking Stages which are personalised to your venue.