Step 1: Create an arena with /WiiSports Addarena (name of arena)
Step 2: You can do this with a GUI or by commands, I prefer the command way. Go to your waiting lobby spawn point and type /WiiSports Setspawn (name of arena)
Step 3: Go to your swordplay arena and stand at player 1s spawn point then type /WiiSports Setspawn1 (name of arena)
Step 4: Repeat the process for player 2s spawn point by walking to player 2s spawn point and typing /WiiSports Setspawn2 (name of arena)
Step 5: You are now ready to play, have 2 players type /WiiSports and the GUI will open up, click your arena name and you will teleport to the waiting lobby, game will start when both players are in