I'd like to run a homeless shelter for runaway kids, or a soup kitchen; it's not really a business, though.
If I were to have a business, I would also like to have a fish store :) It would be called Toad's Fish Soup, and it would look a lot like Pier 1, but full of fish. It would sell various tanks, 1 gallon and larger, all sizes of heaters, sustainably harvested drift wood and hardscape materials and tons of live plants. I could put together little NPT starter kits, with the tank, soil, substrate and plant lights, and regular tank kits for bettas that would include heaters and sponge filters. Would have a Betta Wall of 5 gallon tanks, each planted and housing a single betta available to be purchased. There would be a section of books on fish keeping, different species, etc.
Oh it would be fun :)
The only cure for ignorance is education, and bullying or attacking someone is no way to educate them.