How much to carry depends on where you can get supplies. It changes on a daily basis.
My strategy is to carry enough water & food to get to the next known resupply location, plus a little just in case things go slowly. This is one reason the A.C. maps are nice - you know where that location is.
Every time you are about to leave a place where you can get supplies, take a look at the map and figure out how far to the next supply place. Figure out how long it's going to take you to ride there, and what meals and possible over-nights you have to cover. Then buy to cover that, plus a little extra.
Evening meals are usually some kind of carb with whatever makes it taste good, and some protein, veggies & fat. Example: pasta or couscous with pesto (powdered packet) and olive oil (carry a small bottle), or rice and cheddar cheese, or potatoes and cheese. Add fresh veggies if available (some veggies last well - zucchini, squash, tomatoes, avocado, some less well - broccoli, some not at all - asparagus, lettuce) and fresh or preserved meat (tuna & chicken come in nice portable single-serving size packets). I often carry a hard salami, some parmesean cheese, some spices, salt & pepper. Cheese lasts a long time w/o refrigeration. If I'm lucky enough to be eating dinner near a grocery store, I might buy a bag of lettuce, whatever veggies look good, some sliced ham or turkey, olives etc, and make a salad. If you are really lucky there might be a salad bar.
Lunch can be peanut butter & jelly sandwiches (carry supplies) or crackers & cheese & salami, an avocado, etc.... just buy stuff that appeals to you and can do double duty - salami can go in a sandwich & in pasta). Or you can buy a sandwich in the morning to eat later. If you're lucky there's just somewhere to buy lunch along the way, but again you'll have to look at the maps to see where that might be.
I always have some ride-snacks of some sort (junk food, newtons, candy, energy bars, granola bars, chips) to eat on the go.
For water, I'll carry 3 regular large-sized water bottles, and if it's going to be a long way to the next water, i'll just buy a few liters of water from a store - just regular bottled water - and carry them in a pannier. you can keep the bottles & refill if you want, or recycle and buy more later. I generally don't overnight where I can't get water, since that would mean having a lot of water on board (for dinner, drinking at night, coffee, for the morning ride...) so if you are going to dry camp, plan for that stuff.
Hope this helps!