If you want to participate, you just have to play during a Tournament period in one of the rooms valid for Tournament, using a Deck valid in the room.
Youst play in room that make for tourny with the right deck on tourny time watch the rules
and for tournys that made from pivate you have to post in the anonce that you want to join
Go to a room that has tournaments in it. For you, I'd probably level up to 13 and jon Fight Type 1 room and fight in tournaments there...
I got 32nd place in a tourney, but my winnings haven't come yet. Also, while I was playing, my points didn't show.