By default, RSVP and ticket forms on single events show up below the event details where information like start time, end time, venue, and organizer is displayed. However, you can also opt to move the RSVP or ticket form around to different locations on the single event page. You can find this option under Tickets > Settings > General.
You will see one option for the RSVP form location and one option for the Tickets form location:
