You can if you haven't already joined a tournament (being a non-paying member). Click on the "tournaments" link on the left. A list of all the tournaments will come up. Click on the tournament you would like to join. A list of available games in that particular tournament will come up (there could only be one). Click on the game type you would like to play. If you are eligible to join (rating, membership, number of players join already, etc) then a link will appear above the list of already participating players saying something to the effect "Sign me up for this tournament." Then, when it starts, as long as you have enough open spots for the games, the games will automatically appear on your main page :-)