How solid is your concept? Have you done the investigation necessary to determine if your business idea can work?
To start with, you have to have a clear and limited description of the products or services you plan to offer. I have used the word "limited" intentionally, due to the inclination of most entrepreneurs having to be “all things to all people” right from the start. That creates too much territory to cover. Focus, and start with something you believe are your key offerings. Naturally, you will expand on them as the business grows. Covering too much territory at the beginning may be unmanageable.
Next, you have to define who your customers are, and create a profile for them. Who are they? What are their characteristics? What will motivate them to buy what you offer?
Lastly, how will you reach them?
Performing a feasibility study will test your concept and take you through preliminary calculations, including your revenue stream, expenses and initial capital requirements.