On the Friday before your competition starts you will get an email with your new team details.
You will then get an invite to join your team page on Teamer.
Once you accept the invite you can login to your team page.
You will also get sent an email invite to join the first game.
All you need to do is click 'Accept' or 'Decline'.
There will be a link to download the Teamer app in your email.
It is not compulsory to download the app but it does make it easier as they send you notifications when you have a new game and you can chat with the other players on the messageboard there.