Can I change the name on my ticket?

Not yourself, at the moment. The ticket shows the buyer's name, or part of their email if no name was given.

Going in someone else's place?

At the door, staff scan the QR code. Send the ticket link to the person going. See Buying tickets for friends.

The name is wrong

If the name matters for the event, for example an ID check, contact the organizer before the event. See How do I contact the organizer?