Not really the right forum but anyways:
With a kid, best place is probably Wendy's/Country Style/TDBank on Airport Road at Orlando Dr., there is a safe grass area away from traffic, it's clean and the planes on approach to Runway 23 go right overhead... and it's fairly easy to get to. Alternatively there is a Tim Hortons a little further up but the view isn't as good by far.
The only other "safe" spot i can think of would be the south end of Bramalea Rd. next to Fed Ex (where FedEx hill used to be)... though the police will come kick people out of there on occasion, there is a great view of Runway 23/5 through the fence, just do not park on the FedEx side of the road.
I wouldn't recommend most of the other places with kids, there are either busy roads nearby or the threat of police hassles so it's probably best to stick to Wendy's if he wants to get out of the car.
Places to NOT go with kids:
Terminal 1/3 parking garages, poor view, expensive and annoying police
Terminal 2 garage, construction all around, vehicles moving at high speed at times
along the side of Dixie or airport Rd... just don't.
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.