how do I get approved by a provider

How does a person without references get approved? Correct me if I'm wrong, but it seems like I can't register at places like Preferred411 because I'm retired. Am I S.O.L.?

First, the place to ask about P411 registration requirements is P411, not here.

Second, every newbie faces this problem at some point, when he makes the jump from civvie open-door (AMP, for example) services to private providers. There is no one good answer. If open socials are held, show up. Some providers advertise themselves to be newbie-friendly, or will do other kinds of screening. That's the usual path.