Grab a cup of tea, you're on the list
NewfieCards is a small kitchen party, not a public hall. Every new player gets looked over by the fella who runs the place before the door opens, so that the table stays full of real people and not robots.
There's nothing you need to do. Once you've been approved you'll be able to sign in with the username and password you chose, pull up a chair, and get a hand of Scat or 120s going.
If you've been waiting more than a couple of days, or you signed up for a friend who's expecting you at the table, get in touch with whoever invited you and they'll give Shannon a nudge.