How would someone go about getting their birth certificate and social security card if they don t have an ID?

He needs to start with his birth certificate, in the county where he was born. He may need to gather all documents he has currently with his name on them, and some people who know him, and visit an attorney or legal service. Those who assist the homeless may be able to assist, since they commonly have ID issues.

Anyone who is listed on the birth certificate can request a copy, so it's easiest if he can contact his mother or father and simply have them obtain it.

tell him to go to the social security office

Follow the instructions here http://blog.vitalchek.com/birth-certificates/documentation-station-need-order-birth-certificate-today/ They should accept his school photo id. The payment needs to be in his name so, if he does not yet have a credit card, he can get a prepaid first.

What country are you in?

First he needs to get a duplicate of his birth certificate, which is issued by the county in which he was born. At age 18, he can do this himself. He should phone or find their website to see what he must provide to get the duplicate. With that, he can move on to the social security card. Does he know his number? That will help. He can phone or fine a website giving details on that next.