Hello N.,
My name is M.. I am 33 years old and my only son Nolan 2 1/2. I have flown with him 3 times already, to florida, and have taken him to disney in two of the trips as well. My entire family spent a week in disney in December, we stayed on disney propert and used their bus system and it worked well.
I have flown us air and united out of pittsburgh airport. First, I recommend a direct flight. I planned my flight so that we could wake up at our normal time, give him time to play before we drove to the airport & have breakfast,then let him check out the airport and walk around/get tired out, before we boarded the plane. The airline lets families w/ small children and those needing assistance board first, but I never do, I figure we will be on the plane long enough, so we check out the planes and ride the moving walkway, and he loves the tram, it's a train ride for him. Check everthing but a small bag of toys, food, drinks and necessities. You'll have your hands full with a kid and boarding passes, going through security, getting from check in to the gate which is always so far away. If you can, check in online, print your boarding passes and pick your seats before you even drive to the airport. then use curb side check in- it is much easier than lugging suitcases through the check in line. I've never had any major problems flying with a child, especially to orlando airport, the plane is full of families. I fly mid week, in the afternoon. We are usually ready for lunch/snacks by this time, so after everone is loaded & seated w/ seatbelt on, I give him crackers, cookies, fruit, any kind of finger food, that is time consuming and easy. It keeps him still and quiet, and then he won't be starving later. It distracts him and the swallowing is good during take of and landing to help with the pressure in his ears- kids don't know how to pop their ears and it can be very uncomfortable if they don't. Kids cope better than we give them credit for, your son will probably enjoy it, take some toys to play with during the flight, and if you time it right, he will be ready for a nap and the ride, like a car ride, will put him to sleep. and you can always enjoy the safety movie on the little tvs. read a book. Then let everyone else off the plane first, pick up the sleeping kid, and you are in sunny florida. Have fun. take your time getting to baggage claim. Use the restrooms before takeoff and after landing, the ones in the plane are tiny. You and your son can check out this airport while your husband gets the rental car. use the luggage carts, or the airport employees with the carts - the couple bucks you tip them or the curb side check in guys is worth it. Less stress, more fun.
If you'd like to talk more, have any questions, let me know, I'm willing to help. I think I covered everything you may be worrying about. But don't worry, Go.
M.