In Joomla you do have a setting to let users activate the user account before they can login with it. But in case you;re selling tickets, it might not be user-friendly to have this functionality turned on. Customer has to wait for an activation mail then, which includes a link to confirm the user account creation.
Turn off User Activation in Joomla
- Go to the Joomla User Manager (screenshot 1)
- Choose "Options" on right top (screenshot 2)
- Set "New User Account Activation" to None (screenshot 2)