First off I wanted to give you the link to all Disneyland, California Adventure and Downtown Disney Restaurants and counter services.
http://allears.net/dlr/din/menu/menus.htm
Let me tell you what I do.
For Lunch It may seem simple but PB and J has always been so simple and we have four people and we go to Costco and get fruit it is something that doesn't need a cooler we usually get Orange's and Banana's because with all the not so healthy food a little Vitamin C and Potassium are not a bad thing. Also we have done Lunch meats and cheese but for lunch typically sandwiches are the easiest. I also do albacore salad which can be added to bread if you like, I like it with crackers you can also do tuna but what I do is shredded carrot's green onion, and little pieces of celery with mayo and a little mustard and mix it all up and salt and pepper to taste. You can pre make this and it will last about three day's if kept cold. Chip's and fruit snacks are also great with lunch.
For Dinner as long as you have a microwave you should be good. I pre package dinners before I go it is more work but I take all the meals I make and freeze them then I don't have to rely on the cooler keeping thing fresh for the 8 hour car ride. I make a big pot of soup usually beef stew and add potatoes, carrot's, celery, onion, beef stew meat,and sometimes fresh green beans and then pre package it into individual meals and freeze I get two or three night's out of it. Home made Chicken noodle soup is also easy and very tasty.
I also will do spaghetti with a meat sauce and pre package those meals be sure if you do this to always add extra sauce to the top so after it's been in the freezer and the re heating it is not dry.
Another great meal is I will make chicken casserole the one that's on the Campbell's mushroom soup can it's rice and chicken but I double and triple it and always add another half a can of soup mix to each dish and sometimes I will add corn to it after it is done in the oven I drain the corn the recipe calls for cheese on top but I don't do that because it does not freeze and re heat right.
The other one I did recently was I made a two boxes of Spanish rice I think it was the brand Knorr or Lipton and just ground up meat and added to the rice when it was done cooking then bought some some shredded cheese and tortillas and made my own burrito's the patch of rice and meat you only put into two portions because it is easy to re heat.
Yes this is three days of cooking for me because I like to have the soups cook really long but one it taste ten times better then those pre done meals and I know my family appreciate all the work I do I also think that it is cheaper then all those pre meals. If you want to look for other meals you might like to cook check out www.Foodtv.com I go there for most of my recipe's just remember something's don't do to well from freezer to microwave.
I know this is allot of info but I hope it helps you and Enjoy remember after all this work and planning you get to go to Disneyland !