Would need a lot more information.
Like, are there rank limitations?
Are teams balanced around having some higher/lower ranks together?
Is there different division brackets?
Can teams/duos/trios register together, or is everyone solo and manually placed into teams?
Will teams have access to subs? How will they work, and how will they work if teams are generally tier-balanced?
Do you have rules and guidelines set up or just shooting from the hip?
How many people are running it, and how readily available for contact will they be?
Do you have day/time slots set up that won't screw people over who have work/school at normal hours, so we can schedule our time around this?
Are games going to be spectated/streamed/commentated?
I've seen a lot of tournaments (not just LoL) flop due to bad management, so I'd need to see that the people have their shit together before I signed on.