You could check with the Small Business Administration office in your area.
If you are a senior, the local senior services might offer advice.
I suspect that the rules, laws, and licensing can vary from state, city and county locations. You can check with your local Chamber of Commerce. Some might require liability insurance when people are involved with the property of others, but I don't know. There would be other factors involved if you plan to hire others.
You might try our CNet Small Business forum to see if anyone there can answer some specific questions at:
I need advice in starting my own PC modding/Customizing business. I need help in where I should post advertisements for free, and many other things PC modding/Customizing businesses need to start