To enter any Tournament mode first save the game one hour before the start of a tournament. For example, to fight in the World Tournament (which begins at 07:00) keep entering and exiting Tournament mode until your clock reads "06:00". Now exit Tournament mode and save the game under options. Now enter Tournament mode and there should be a big "Welcome" sign and a picture of the next tournament should appear. Enter the tournament. If you want to fight in a different level then go to options and load your saved game file. Now enter the tournament again and repeat if necessary until the desired level is selected.