You can see contacts who have signed up for your event using Event Signup Page (previously called as Self - Registration).
Places they appear in your platform
1. On the
...
Event page itself
When someone signs up for one of your events using Self RegistrationEvent Signup Page, they will appear on the event’s guests table
2. In the Contacts App
You will see those contacts in the Manage Contacts page
You can use the Contact Filters to filter to find people who have been added to that event