Ok, so if I show my did to someone's they're going to reach out to the method and ask for verification. How does the method place know that the person using the did is the right person? I assume it's some kind of federation? They send me over to the method place, I authenticate, and get kicked back?

Every method currently has different answers for every single one of those questions, directly leading to Google and Mozilla's complaints here that there's already a "registry" of 50+ methods, no actual standardization among them, and it's all punted to "ask the method".