First rule of business is to make money. This is offtrack but if they need to make financials mandatory in school, because so many people get duped in various ways with their money, with high interest rates and that.
Anyways a business would be great if you owned the land and didn't have to pay commercial fees like the condo fees or maintenance fees. You would have to sell a lot of brakes and other things to customers all the time. You see the advantages of being your own boss, but also you would bring all that stress home.