To join a Lodge, open the Chat in the main menu and click the the Lodge tab. If you are not yet part of a Lodge, you will automatically see a selection of suggested Lodges to join. Press on the Lodge name to see a list of its members. Press  to join.
You can filter Lodges by region pressing the Region button, or use the search bar to look up a Lodge by name.
If you have one or more Lodge invitations, you can review, accept or dismiss them in the Invitations tab. You can also set your account to let other players send invitations to you or not.
If you are kicked from a Lodge, you can only join back in if you are invited by a member of that Lodge.