I would think that just as a practical matter, operating your writing club as
a sole proprietorship might be easiest in terms of taxes, licensing, etc.
Essentially, you might be accepting the burden of things like a business
license, doing a Schedule C form inside your tax return, etc., in order to
avoid complications associated with nonprofit corporations or associations,
etc.

Business licenses are issued by communities. Your city clerk's office can
tell you whether you need one. You will definitely need to register your
business name and entity type with your state or county agency that handles
such matters. You may also need a sales tax permit if your state collects
sales tax on services.

Hi Danny, to find out if your business would need a license use our "Permit Me" tool.  It will let you see what you'll need based on the state you operate your business in. Hope this helps!