Hi, I just created the region New California. I wonder now how do I get a WA delegate with one member in the region? Do I simply have to wait for more members?
I don't think you're in the right forum - this stuff would belong in Gameplay.
To answer your question, you cannot get WA delegacy with only one nation in your region. You would have to wait for more to come to your region with at least two WA members.
It’s also not very easy to get another WA nation to join your region, at least not raider ones, which you may get if you don’t remove “Executive” power from the delegate.
I’d suggest you read this for more about executive authority, and this to learn how to grow out your region.