Who can I call to speak with someone who can tell me what I need to know about starting up a small business?

The Small Business Administration office in your area.

Another good source is score.org

In the US anyway, you can start a small business at home with absolutely nothing, as long as you don't need a permit from your town to operate out of your house.
If you are opening a store front, you start with your town for the permit, and your state for the license.
If you will have employees you get a federal EIN from the IRS, and use that number for your state. Having employees is a huge step with a lot to know and do, and I don't recommend it to start.