I'm 20 years old, I've never been to school, and I don't know my SSN.

So, I have no idea what my social security number is. Nobody seems to remember the number and the card itself was lost to time. I've asked around and heard various solutions, like using my school ID to prove my identity to receive a new card, or hiring a lawyer, but neither of these options are applicable to me as I never went to school, and my family doesn't have the money for a lawyer. The only paperwork I own is my birth certificate, but that on it's own can't help me with anything. This is a problem that's existed my entire life, but it's only recently gained my attention as I slowly started to realize I am incapable of living any kind of adult life without my SSN. Currently I'm living with family, but it's not a permanent living situation and soon I'm going to have to be able to hold my own, which I cannot do because I can't get a job without proof of ID. I've tried everything I could think of, and everything else I've been told to do, but none of it has gone anywhere. Given my past, I'm not really knowledgeable on how the world functions, and things like this completely elude me. So I'm hoping this is just a problem that has a clear solution I'm not aware of that someone out there knows about, Because I genuinely have no idea how I'm supposed to proceed with life from this point forward. If any of you have any kind of ideas, even ones you're not entirely sure of, please share them.