How do you join a tournament?
You will likely have to wait until you have completed five rated online, not live, games. There is a possibility a Tournament Director has changed the default to zero games. Do not time out in your current online games.
On the Play menu you will find "Tournaments". From there you can find http://www.chess.com/tournaments/upcoming_tournaments.html
Basic members can join any available official tournament, they start on the first of each month. Five completed online games required for basic members.
Basic members are limited to one member-created tournament at a time. Once you find one you like, click on "Join Tournament". Try to join one that is nearly filled. There can be a long wait for a member-created tournament to start.
How do you join a tournament?