You can register someone else for the same event after checkout or from your dashboard.
After Checkout
First, you register yourself for the event and complete checkout. Once checkout is completed, select Register Someone Else. This will take you back through the registration process to register and pay for the second person.
From your Dashboard
If you are already registered for an event and want to register another person for the same event, select Register someone else from your Dashboard Tab .
If you want to register someone who is not listed in your account, you can ask them to Transfer control so that you can register them.