You didn't mention which route you're taking, so some generic advice:
I wouldn't worry much about food since you can pick up what you need along the way. Most gas station sell food anyway. I carry just enough for to make two or three small dinners in case I roll into a campsite in a remote area or set up camp too late to hit the stores. Make sure you have water...not just for drinking, but also for cooking. I bring two canteens to fill up at water fountains along the way. Buying bottled water is expensive.
If you're dining out the whole time, it's also going to get expensive. I pack a
few little one-serving cans of Chef Boyardee, some drink boxes, ramen noodles, fruit bars, instant coffee and/or tea bags...you get the idea. Be inventive, but find stuff that won't spoil and is small and easy to transport. Pop-Tarts, for instance, make a quick breakfast or snack, but usually deteriorate into broken pieces on a trip. Don't forget a cook kit. I'm still using one of those boy-scout cook kits with a small primus stove...You can't count on weather dry enough to make a cookfire every evening.
Make sure you have good rain gear, obviously....
And warm clothing, Even if you are travelling during warm weather months, it can get cold in higher elevations and day/night temps can vary wildly.
Pack a sweat shirt and layer as needed. Wearing your rain gear, even when it's not raining, is a good windbreak against the cold.
If you can't sleep at night, you're not going to able to ride safely all day.
The worst mistake I ever made early in my touring days was to assume that since I was traveling out west in the summer, all I'd need was a light felt sleeping bag. I darn near froze my backside off at night more than once. I once ended up sleeping with all my riding bear on, including the boots, and still froze. Luckily, I had tossed one of those metallic space blankets in the luggage and while I wasn't comfortable, I didn't get pneumonia.
I have a fairly expensive REI bag these days, mostly because it's warm, but also because it packs very small.
For the budget traveler, you can try this:
Any decent sleeping bag you can find, even at the thrift store. Make sure the zipper works.
Then get another thin, cheap bag to put
inside that other bag if you need more warmth. I bought one for $6.00.
And pick up one of the space blankets I mentioned earlier. NOTE: They are not breathable...don't cover your head. Also, they will condensate.
Get a watch cap. That'll help keep your head warm.
Lastly, sleeping on the ground will sap away a lot of heat. Find and inflatable something...even a swimming pool raft to put your sleeping gear on.
Hope this helps: I got more.