Online registrations or RSVPs are attached to Events that are added to your calendar. You can enable online registration for any native event in your calendar. Online registrations can not be accepted for events that are imported from Google Calendars or other online calendar feeds.
To enable online registrations for your event, simply click the "Enable Registration" checkbox for the event. Also make sure that Registrations are enabled on your Events configuration page.
You can also take payments for online registrations. Payments can be configured in a variety of ways including tiered levels, optional add-ons, etc. You must also subscribe to the online payments / online store module in order to activate paid online registrations.
It is possible to customize the online registration form by adding text fields and drop-down selections. This allows you to collect additional information during event registrations.