One suggestion, I've volunteered with my kids for the air show, basically you keep stupid people from ignoring the ropes and signs as they try to wander across protected areas. It gets you free parking, a free shirt, and a spot on the beach. Down side is you get there earlier and stay later but they provide drinks and lunch.
My then 5y did the ride from Cedar Creek to Jones Beach, getting there isn't the issue, its the return trip, and after a day of watching planes and playing on the beach he may be too tired to ride. We did best with a trail-a-bike, which lets him pedal but you're doing most of the work. The one I have was bought by a friend when their oldest was little 24 years ago, it went through her 3 kids then my three kids so it isn't pretty, but it is solid. If you'd like to try it you're welcome to it.