Registering for an event as a guest can only be done through the individual player account, the coach or manager cannot register your child as a guest through the team account.
Log into your child's player account.
From within the player account, click "Events"
Then click "Search Events"
Search for the event by typing in the event name and clicking "Go". Once you find the event, click "Register as Guest Player" under the event name
To enter yourself into the Guest Player Pool for the event, click "Submit Application".
*once you have been entered into the guest player pool, the team will need to claim you from their team account