Don't worry!!!
Also, give yourself plenty of time - don't want to add rushing on top of the first time flying jitters.
You will love Song. The Direct TV keeps the kiddos occupied. It's a good idea to take your own headphones if you have them. The ones they hand out can really bug your ears after a while!!
Also, they have a cool feature that lets you watch the progress of your flight on the TV. I loved that - I have a very short attention span on flights - can't wait to get to Disney!!!
It's a good idea to chew gum during takeoff and landing to get your ears to pop, but I've never really experienced any significant problems with this.
My husband had a couple of the sandwiches that they sell and said they were delicious!! They have some cool snacky things for the kids too. Look on their website for menus.
Go with the flow. There very well may be some delays, etc. (That's air travel in the US these days.) Take as little carry-on luggage as possible. Just makes it easier in the airport, on the flight, etc.
The last time we flew, you had to take off your shoes if you didn't have sneakers on. Sneakers were OK for some reason, but all other shoes had to be removed to go through security. These things change all the time, so it could be different when you go.
Remeber, you will be on vacation, so have a laid back attitude, and it will all be good. (A Song Appletini on the flight couldn't hurt either!!!)
Have a blast!!!!