Does Event Espresso give you the option to create a database of attendees? If so, how does it know when a person registers for two events that it is the same person? Does that require a plugin feature?
That’s a built in feature. You’ll see a list of attendees (labeled “Contacts”) by going to Event Espresso > Registrations > Contact List.
When someone inputs their first name, last name, and email address into the registration form, and it’s a match with the information they input for a prior registration, it will sync the new registration to the existing contact.