Here is a grocery list that I used for a trip a couple of summers ago. We had 3 teens and a child with us. I used Garden Grocer or one of those services, so I was quite explicit in my ordering. I usually get some nice cheeses and crackers too, but I see that wasn't on the list. I always pack kosher salt, a small pepper mill, and Crystal Light flavored ice tea packets too.
Produce
1-lb bag baby carrots
8 medium bananas-not too ripe
10 medium apples-gala, fuji or similarnot red delicious
1-lb red seedless grapes
Shelf-Stable Fruit Juice
1/2 gallon white cranberry juice cocktail (Ocean Spray)
Sodas/Other Beverages
6 (12 to 16-oz) bottles Gatorade fruit punch
1 6-pack Diet Coke 12 oz. cans
1 6-pack Diet Mountain Dew 12 oz. cans
1 6-pack Dr. Pepper (6- or 12-oz. cans)
8 (12- to 16-oz) bottles water (store brand okay)
Cookies/Snacks/Candy
1 medium package Oreo cookies (original variety)
1 bag (10- to 16-oz) peanut butter M&Ms
1 bag Chex original snack mix
1 bag Chex chocolate/turtle snack mix
Cereal
1 box Cinnamon Toast Crunch cereal (regular-not huge box)
1 box Reeses cereal (regular-not huge box)
1 box Quaker Oat Squares cereal (regular-not huge box)
Meat
1 1-lb pkg Hillshire Farms lil smokey sausages (prefer light if available)
Dairy
2 gallons skim milk (prefer milk not treated with BST, but will take it)
1 dozen large eggs
Other Refrigerated
2 (1/2-gallons) Floridas Natural orange juice-no pulp
1/2 gallon Dole Strawberry-Orange-Banana juice