Hi Isa.
Welcome to Townsville.
I was just out today with the locals at Pallarenda Beach (just 10mins north of the main city centre).
That's the best place to kite and there is plenty of room for everyone, and great for beginners. I am assuming you're not a beginner of course, so you'll find plenty of friendly locals and kiters all happy to help out if you need to know anything.
There are other great spots too depending on the winds. Alva Beach (1 hour south from Tvl) is perfect with flat water lagoons and again plenty of room. Further north you have other spots as well like Lucinda, Saunders Beach, etc. But they generally tend to be visited by more experienced locals when they know the winds are precise for those areas.
Generally Pallarenda is the place to be for most kite surfers in Townsville, and right now you're in luck. Winds are picking up tomorrow (on your arrival) around at least 15knots, and predicted to stay windy for most of the week. why not hop into InTheLoop kite shop and have a chat to Marvin or Flo. They will point you in the right direction.
Sorry Marvin. Had to steal your thunder.