Fox's Journal is a must read but maybe not the first. I got a good overview from Friends For 300 Years. There's an updated edition: Friends for 350 Years, but I haven't read it yet. And, no, I didn't read the other one 50 years ago.
I am also seeking and was raised in a liberal protestant Californian home. I don't have answers for you but share your interest. I heard that the Journal of George Fox was a recommended reading. Maybe it could help us answer these questions. Best of luck.-Amy