Commercial Outdoor Furniture How Do I Create A Database For Commercial Clients Including Builders, Developers And Project Groups Etc?

How do I create a database for commercial clients including builders, developers and project groups etc? - commercial outdoor furniture

I was with a position of the data used entry, so I have no idea where to start, nor any of the information. My boss wants to sell their products in outdoor furniture for commercial customers, as they are already in employment are in a business for private clients. How do I start?