I'm so glad that you're going to be making it our way to see DLR !!! And please do send gratitude towards your direction for your son. He truly is a hero! God bless him and you & your family.
There are SOO many things that you really should try out and its soo hard to choose. I've been to DLR almost every year since i was about 5 and i'm 23 now

It certainly has changed over the years, but nonetheless the magic is always the same. There are certain things that I LOVE to aim for and understandably it will be hard to do in one day. Luckily you will be available for a couple, so you'll be able to spread out the experience and enjoy it all at a pace. Here's some things I like to do :
@ DL :
Main Street USA: Eat breakfast @ Carnation Cafe (its just nice to see all these smiling faces as they enter the park and the darn smell is just hard to resist!!), take a look in the shoppes near by( the architecture itself is a sight to see), also if you want some clothing check out the clothiers and nearby shops (they don't sell the clothes anywhere else but in DLR).
Adventureland: Get a Dole Whip at the Enchanted Tiki Room (its great), go on Jungle Cruise and Indiana Jones ! Eat some BBQ @ Bengal BBQ.
New Orleans Square: Go on Pirates of the Caribbean!!!, Check out the Shops in the area (especially the glass one, the stuff in there is beautiful), go on the Haunted Mansion, Maybe eat at the Blue Bayou or Cafe Orleans (the cafe has some of the same items on the Blue Bayou menu, but at cheaper prices esp. if you at lunch), watch the Pirate Show on Tom Sawyer Island (you don't necessarily need to go on the island to see it!), watch Fantasmic !!, eat a Turkey Leg, make sure you stay hydrated !
Critter Country: go on Splash Mountain & The Many Adventures of Winnie the Pooh, get a Tigger Tail at Pooh's Corner. Make sure to get some character pictures in!
Frontierland: Go on Big Thunder Mountain Railroad, check out the food!
Fantasyland: I'd just say go on everything, its all SO nostalgic!!!, check out the castle and try to see the evil queen above Snow White's Scary Adventures, look at the golden spike when you cross the castle (it is the original geographic center of the wagonwheel shaped park... it is not longer the geographic center though).
Mickey's Toontown: Check out the town its so cute!, go on Roger Rabbits Car Toon Spin.
Tomorrowland: Make sure to hit up all the rides here too ! Take a look at the vegetation (its ALL edible!!!), watch the Jedi Training Show (its kid oriented but SOO cool), If you're going to go on the Train, you should go from here because its fun to see.
@ DCA:
Hollywood Backlot: Go on Monster's Inc. (my fav ride!), watch the Aladdin Musical (its amazing!), go into the animation area (its so wonderful to see!!), go on the Hollywood Tower Hotel Twilight Zone, get a smoothie,
Sunshine Plaza: make sure to watch the parades (esp. Pixar Play Parade & the Electrical Parade), eat some good food!
Paradise Pier: California Screamin!, Toy Story Mania, the Maliboomer, Orange Stinger (go on all these!), make sure to get a Tinker Bell Twist!
Golden Gate: go on Soarin' Over California and Grizzly River Run!!
@ DTD:
I recommend going to these places :
Ralph Brennan's Jazz Kitchen
House of Blues
ESPN Zone
Catal Restaurant
Starabilias
I recommend also doing Finding Nemo in the morning, Fantasyland, and Toy Story Mania because it gets soo packed. Really take advantage of Fast Passes, they save a load of time!
Hope you have an awesome time !!