My experience as a FFL dealer is getting dated but I still urge you to do your homework before taking that step.
You must specify a licensed premise and business hours. Since you are becoming a business, don't forget that you'll need a WA State Business License and a WA State Firearms Dealers License. The business license is a one time fee and then you pay taxes on your annual sales. The firearms license must be renewed every year.
Decide now whether you will be just selling to buddies or whether you're going to actually retail. If it's just for yourself and a couple of buddies, personally, I would say it's not worth it. If you have any questions, feel free to PM me. I started off working at the wholesale level with RSR Wholesale, then dealing out of my home (bad idea), moved to storefront (what a pain in the behind), and then quit it entirely. It was real and it was fun...but it wasn't real fun.