You have to pay your taxes and reinvest in your business. A lot of people take the money out right away and they don't have any money to run their business. For example, a woman who delivers papers has to reinvest 1/3rd of $12,000 pay into her car for brakes, struts, etc., because the car will wear out from the job and there are always those unpredictable things that you have to pay for. Someone hit us and our deductible was $500 and we waited a year to get it back which means if your business needs insurance, someone has to cover accidents. Equipment can get lost, stolen or break. Sometimes in order to compete, you have to invest in new things.
Some businesses have to deal with broken things and the way they do that is to charge twice as much or four times as much. If you had a retail business, you have to understand that some items are coming back and that will come out of your profits.
You have to consult a lawyer and you need a book keeper. A book keeper will teach you how to keep your books.
We had to contact our township, pay $10 a year for a business license and they usually want to know where the business is located and what you are doing; in your basement, how many people come to your house, etc.
You might have to carry insurance. It all depends on what kind of business or work you are doing. Handymen now have to carry $50,000 insurance to work on people's houses in my state.
Some of my neighbors have businesses and they park their trucks on our street and it can really annoy people.