I would do something business to business instead of business to consumer, but that's me. Can't say anything about food trucks but at least you're doing your research.
Anecdotal, but in the franchise company I work for a lot of people that come from government jobs struggle or outright fail. Most of them complain about working around lazy, stupid people, and they're all gungho about going into business for themself. Usually reality smacks them in the face; they knew owning a small business was going to be hard, but not THAT hard.
You'll want to calculate your burn rate and break even (e.g. need to do $20k in sales a month just to cover expenses before you pay yourself, divided by an average of 22 working days, which is $909 a day, or $113 an hour, which is $1.89 a minute). Then you'll need a marketing plan (door to door marketing, handing out flyers, email campaign, chamber/BNI/rotary networking, telemarketing, promotional products, events, EDDM flyers), and trend your sales month to month and see how long it will take for you to turn a profit.
As for payroll and staffing, with the way the economy is today and good labor being hard to find, you can to do 2 things: Make your place of business something that your employees at least find bearable, and consider their needs for money and set their job goals based on that. Employees will take a little less to work with a good boss/manager (more money in your pocket, right?), and if you can set up a salary in the beginning that is manageable for them, they won't take the job and simply be looking for a higher paying job on their first day. Our franchises are 2-4 employees on average, and the most profitable locations have a good team with employees that could get paid a little more elsewhere, but the job security and a good boss is just enough to stop them from doing so.
If you want to PM me I'll tell you more and which company I work for if it'll help or give you some ideas.
Lastly, go to some trade/franchise shows over weekends to get an idea of what kind of businesses are out there.