Yes, you do need a license. However, you shouldn't have to have a license in Amherst county to sell your services there unless that's your primary place of business. Much like any business owner on here shouldn't need a business license from Amherst county to sell to customers in Amherst county.
If you incorporate as a single member LLC, then the IRS doesn't usually consider you to be an employee either.
If you incorporate as a single member LLC, then the IRS doesn't usually consider you to be an employee either.