First of all, no spreadsheet or software will be able to tell you what to charge. They may help YOU calculate the numbers.
Second, the MAXIMUM you can charge depends on your market and your competition.
Third, the MINIMUM you MUST charge is whatever it takes to pay ALL your costs and put some money in your pocket. That means you must know ALL your costs, overhead
- Licenses and permits,
- business cards & flyers
- other annual costs
- Food supplies
- Packaging supplies
- other supplies, paper, cleaning agents, printer ink, pencils, etc
- car and/or truck expenses
- telephone and internet
The above are just off the top of my head, you know far better than I what your expenses will be.
Once you know your costs and you know what your competitors charge, you can decide what you should be charging.
If your product(s) are superior to your competitors, then charge what they do or maybe a little more.
If your product(s) are about the same as your competitors, then you'll have to compete on price, which, IMHO, is the road to bankruptcy
Initially, a pad of paper will be a big help.