How do I set the menu for an event?

On the event page, in the Meals box, type the options for each course: starters, mains, desserts. The menu belongs to the event, so every floor plan in it shares one menu and one set of choices, and only you and your team can change it.

Each course becomes a dropdown column in the guest sheet, and the catering report counts the choices. See What is in the catering report?