Per the ATF, before you can even apply now, you have to have a buisness liscense and a brick and mortar structure for conducing your business. The days of shade tree FFL holding are long gone. It'll cost you at least $100K to get rolling.

Dealer direct status is largely a bad idea for an up and coming gun shop. There are certain companies (benelli for example) that you MUST deal direct with. For everything else, go through wholesalers, you'll get MUCH better terms. Ellett Bros, Bangers, Henry's, Dixie, etc etc.

Good luck... I wouldn't want to try and make it these days..... you gotta have a very specific niche to make it small, or have a very isolated market in a place a larger store won't build and slit your throat.