Ahoy, Jessica!
How exciting to hear that you and your son will sailing with Captain Mickey for the very first time. You will be in for such a treat! There is so much to do and experience onboard the Disney Cruise Line ship, that I should warn you -- you might want to sail again soon, right after you disembark from your first cruise. :-)
Your cruise cost includes your meals and drinks while onboard. Disney Cruise Line has a very unique rotational dining system and it makes it very easy for guests to know which main dining restaurant they'll be eating at each night. On top of that, you've got a dedicated dining team following you each night at the 3 main restaurants that you'll be visiting each evening. Specialty and alcoholic drinks are an extra cost. The 24-hour room service is also complimentary -- so make sure you get your little one some warm cookies and milk delivered before bedtime. It's a night time treat that everyone in our family loves! All the quick service dining areas by the pool are also included already. You really don't have to worry about going hungry whenever you sail on a Disney Cruise... there is plenty of all-you-care-to-eat fine food, ice cream and all sorts of goodies onboard.
I hope this helps with your planning, Jessica. At least, you won't have to figure out a separate food budget at this point -- since you'll have everything already included. If you decide to eat at one of the Adult Exclusive restaurants,
Palo or Remy -- there will be an extra fee that will be added to your stateroom account. Make sure that you make early reservations for these though, since they do book quickly.
Have a great day!
~ Dolly