Last time I looked, you need a FFL as a MANUFACTURER of ammo and ammo components, but not as a seller. Business license would be a real good idea. As far as storing at your house- maybe. Depends on zoning laws where you live- shipments delivered to house, quantity, etc. Would start with the local fire marshall, and see what regs THEY have, and with zoning (running business out of your house. St Marys- probably not an issue. Baltimore? Issue. And just FWIW, the stuff that does NOT get sold at a show has to get lugged back home. Hefty, that stuff is. And over 66 lbs in a shipment is going to be HAZMAT- do you know hazmat shipping requirements?
What we have here is... failure- to communicate.