Can I change the name on my ticket?

Not yourself. The ticket shows the name on the buyer's account, or part of the email it was bought with if there is no account or the account has no name.

Going in someone else's place?

At the door, staff scan the QR code, not the name. Send the ticket link to the person going. See Buying tickets for friends.

If you want the ticket to be theirs, transfer it. A transferred ticket shows the new holder, with "Received from" you. See Send a ticket to a friend.

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?

If the email on your order is wrong, the organizer can change it. See I typed the wrong email at checkout.