Dude food trucks are a cheap way to get some cash without the crazy permits and regulations that plague full scale restaurants, so I think you've made a good decision getting the truck...
But cheese and crackers? Not trying to be a cock, and I only read the first page of this thread, but that's a completely asinine idea. Buy a dozen refrigerated vending machines instead and outfit them to hold/vend your product.
The bread and butter (no pun intended) of the food industry is in taking something from an unprocessed basic form for as cheap as possible and then using your skill and know-how to use and transform the unprocessed item into something special that you can sell that people can't get elsewhere.
People can buy crackers and cheese. Unless they're getting something original or at a cost that blows competition out of the water, you're shit out of luck.
Think of it this way- people have been vending/selling shit like hot dogs, burgers, pretzels, beignets, sausages, popcorn, tacos, kabobs, fried dough/funnel cakes, cinnamon rolls, cookies, cupcakes for a fucking century now.... and no one ever thought to sell crackers and cheese?!?! It's not because they haven't already thought of it, it's because the idea blows donkey dicks. Like the idea actually sucks the cock and swallows the cum from the dicks of donkeys. Sorry, even if vineyards are interested, you really gotta step your game up to keep them interested. A fucking plastic wrapped weed bag of sliced Cabot cheddar and some ritz isn't going to blow anyone's mind, unless the customer base is retarded and handicapped.
Wait- that may be your in.... park the truck outside of special Olympic events and retard shelters.