So jealous, you will have an incredible time! I love New York.
In terms of places to stay, how long will you be there for? If it’s a short break you’re probably best staying pretty central, so you don’t end up spending lots of time travelling back and forth on the subway. I recently stayed at the St Giles Tuscany which was very nice and quite cheap by NYC standards. I have also heard good things about the Pod hotels (if you don’t mind a small hotel room).
Pick up a card for the subway from one of the stations when you arrive, I think you can get them for 3 or 7 days unlimited use (but I may be mistaken)!
Things to do... there’s so much! If you want to see the skyline, I would recommend top of the rock over the Empire State Building, it is cheaper and the view isn’t obstructed by metal caging.
If you get good weather, a walk over the Brooklyn Bridge gives you a great view of Manhattan and Brooklyn.
If your DS is into sports, you could see if there are any games on nearby whilst you’re there?
There are also loads of great places to eat! I’m taking a guess that your son will appreciate stuff like burgers and pizza? Juliana’s pizza in Brooklyn is great, and there are loads of great burger places including Shake Shack (which is a chain but teens will probably love it)!
When we went, we did a good tour with Foods of NY. If you’re into food, I’d highly recommend it.