You don't necessarily need a lawyer. I see you're in Olympia, contact the Washington SoS either in person or via phone or email. Once they know it is for veterans, they'll most likely walk you thru the process. (I was involved with something similar in NC.)
As for running the charity, MAKE SURE your books are always in order. If there is one thing this country holds sacred, it's veterans being scammed (or at least accusations thereof.)