What type of tournaments? For daily tournaments just play during the scheduled time on the proper game rooms. For player-organized tournaments check the boards for active tournaments and check if you can join.
Depends on the tournament rules. Most of the time players are put into groups the thing is you must play everyone in your group at the danger zone. This matches depends on when you and your opponent might be available.
The Urban Rivals team is made by lovers of all kind of Collectibles Cards Games and Trading Cards Games like: Magic the Gathering, Dominion, Vampire, Yu-Gi-Oh!, Pokemon, Wakfu TCG, Assassin Creed Recollection, Shadow Era, Kard Kombat and Might & Magic Duel of Champions.