Long boring post about the business of food trucks.
The most profitable food trucks are those with the simplest menu, quality food, and great location. Usually its best to go where there are other food trucks, unless you plan on delivering to other restaurants and stores. Food trucks or restaurants that are by themselves have a extremely high failure rate.
Food trucks also are not any cheaper than brick and morter restaurant. They actually can be much more depending on your local codes. Expect a cheap import to run about $30K to $70k, plus the cost of the truck itself. You can get a setup in a nice gas station or strip mall store for less and with less code enforcement and insurance requirements. Many of my friends food trucks run closer to $250,000 and their street rental (Yes you usually have pay rent where ever you park the truck or you can be ticketed by the city) in some cities can average $10000 to $20000 a month depending on the city. In most cities though expect to pay a business and city fees about $150 to $500 a day for good spots. For 2nd tier spots $75 a day +/-. The last truck I built for a customer was in St Louis, MO. He bought the truck for $14000 used, my services cost and equipment was $22,000. City inspection and state and county license ran him right at $800. This was a taco truck. He has to store all his inventory ina licensed commissary which cost him $550 a month. And his parking spot in Downtown St Louis near the ferris wheel and arch and all that ran him $950 a month. His gasoline and propane cost for cooking and power ran about $40 a day. His sewage and water ran about $75 a week. And everytime he changes cities he has to get a new inspection and license for that city and negotiate all the taxes, fees, insurance, utilities and rent all over again. Not to mention kitchen and server help is averaging close to $15 to $25 an hour, which your cost is about 20 to 30% higher than that for social security, worker's comp, and liability. If you are open 8 hours to the public expect 14 hours total day length to account for opening, cleaning, stocking, and closing down each day. Maybe longer if you have to drive the truck to a commissary to park.
Also every item you add to menu magnifies the cost of operations not by 2 but by 4 to 6 times. because you have to carry all ingrediants cost, labor cost, marketing and display cost and you must pay rent to store all that stuff. Many cities here in USA (I dont know where you are), you have to do your prep and cooking in a licensed commissary.
My last food truck I operated I sold BBQ out of a gas station and used my truck as a kitchen, and the gas station as the commissary. I actually negotiated that the gas station owner paid for and provided location, storage, utilities, and food ingrediants. I paid insurance, inspection fees, and labor. We split the profits and did pretty well.
Your concept of Cinnamon rolls, Sweet rolls, shokupan, cookies (maybe three types) would be a simple and profitable way to go. Maybe offer traditional coffee- but avoid expensive coffee machines that require two and three phase power requirement and cost $1000 plus. Your coffee vender usually will provide you free coffee machines and carafs. Same with sodas you can usually get coolers or fountain machines free from your soda venders.
Hope this helps. I mean its really off topic for Godot- unless you created a game in godot or your restaurant. Maybe a gamified menu system with avatars and stuff.