The ticket status can be set to open or sold-out. Similarly, the ticket visibility can be changed to hidden in order to hide it from the attendees.
If the ticket status is open. It would allow the attendees to buy that ticket.
Once all the tickets are sold. The status can be changed to sold-out.
Ticket status can be done by editing the ticket and changing the ticket status.
Step 1: Select the ticket and click on 'Edit'.
Step 2: Change ticket status to Sold-out.
Step 3: Click 'Save'.
If any ticket has been purchased from any category, the particular ticket type can not be deleted after that. However, you can hide the ticket from the attendees by changing the Ticket Visibility to Hidden.
Step 1: Select the ticket and click on Edit.
Step 2: In the Edit ticket change the Visibility to Hidden.
Step 3: Click 'Save'.