I’m sure someone has built something similar. If you are switching from studio to studio pro, I would recommend working through the rapid developer and intermediate developer learning paths in the mendix academy here: https://academy.mendix.com/link/paths
These quickly show you how to work in the modeler, and cover all the concepts you need to build an app like the one you have mentioned!
You haven’t asked a specific question or indicated where you are struggling, but the basic idea here is you are creating an application that allows anonymous users to view the pages where you show the events / ticketing information. Then have a custom login page where the user can use credentials to sign in as a specific user role, where they would be directed to a role-specific homepage to view their own tickets.
Give the learning paths a look, master the processes they teach, and return to the forums with specific questions if you are stuggling on a specific piece of the app. Good luck