1) My last sustained multi-month self-supported tour in the US cost me about $25/day, split roughly between food and lodging. That included one motel stop per week and one restaurant meal per day, on average. I often went days without stepping under a roof (other than the occasional public toilet). One recent five day combined bike/hike trip from home I went unsupported, camping on public land, and didn't spend a cent other than the cost of groceries from home and one tire patch.
2) I have extensive long distance hiking experience and have developed a stoveless travel style. I carry whole-grain muesli (which I make myself from oats, nuts and raisins), tortillas and peanut butter, bags of nuts and raisins for snacks, Fig Newtons for a quick breakfast, as much fresh fruit and veg as I can carry, and whatever else looks good while shopping.
3) I cycle a lot all the time (100 miles per week) and never need to train for a trip. One trip started out with lots of climbing in Washington State, like 5000' per day for five days, so I did train on multiple days of serious climbing for months before that trip. I wanted the climbing to be fun, and it was. I heard some good advice once, to train for 30% of your target sustained daily mileage (if you have such a thing). On one long trip I had a goal of 500 miles per week, so I cycled close to 200 mile weeks in the months leading up to that ride, and that left me very well prepared. I tend to have goals on my trips and enjoy meeting those goals. I know that differs from others' travel styles.
4) I prefer a plant-based diet all the time, at home or traveling, but not too strict. It's a simple, inexpensive diet to fit my lifestyle. I'll stop for a pint of Ben & Jerry's or treat myself to a cheese and veg pizza when I start losing too much weight on a bike trip. I don't get cravings normally, but I will satisfy them while cycling or hiking. I'll eat more packaged and fried food while touring.
5) I tour on inexpensive, sometimes used bikes, anything that will take a rear rack. My current bike is a low-end gravel bike with road tires, with a 2 x 11 drive train and mechanical disk brakes. I got it from a guy who'd been in an accident with it (damage to the rear rack and bent der hanger) and was dumping it for a low cost. Before that was a half price sale at REI for their Randonee touring bike, $350 in 1996 and that lasted over two decades. I used a 1983 Trek 620 touring bike for a few years, a gift from a friend, on lots of short tours.
My style developed gradually over four decades of touring and backpacking. That's probably the case with everyone responding here. We're all going to have different styles, each one valid. I enjoy touring with others, seeing other styles, sometimes learning, sometimes teaching.