To start a business, one needs capital,( Mollah).
1) Get a business Certificate form your local city hall.
2) Find real estate in your town of operation.
3) Get a business card, or a box of them.
4) Go around asking people, specifically businesses, what service they want done to their computers that they want to see improve.
5) Get your necessary tools and equipment form a tech manufacturer.
6) Open your store with some inventory,( like some Athlon dual core processors, mobos, and PSU's on hand for consumers that pass by.)
7) Begin to sell your services.
NOTE:
A degree, even an AA, in IT can help, unless you are doing a cleaning service.
Starting a business is fun but can be dangerous.
Remember, one will not make money the first 18 months of service.