Business license requirements vary from State to State and even county to county. I'd recommend you seek a Business Law attorney. See Avvo.Com under Find-A-Lawyer. Good Luck in your business.
The State of Louisiana no longer requires occupational licenses for businesses. To add to what the out-of-state attorney said, regulations vary from parish to parish. Rather than checking with an attorney to start with, just call the Bossier Parish finance department and ask, "I'm selling things online. Do I need a license?"