My two sons are ASD -- aka extremely socially awkward, especially my oldest. It is their good fortune that I happen to be unusually socially observant and, at times, reasonably smooth (when my health issues aren't fostering research for a future book called "How to win enemies and alienate people"). Some things that helped:

Addressing underlying health issues.

Shadowing -- i.e. watching me do stuff first, learning by example.

Apprenticing -- an extension of shadowing where they took over pieces of the process as they became comfortable with them and I filled in any gaps until they had the whole thing down pat.

I also started an email list at one time tailored to an interest my oldest son had. With the assurance that mom had his back because I was the moderator, he bloomed and rapidly became the life of the party. He finally got to share with other people the sparkle I had long known and adored. Having experienced it once, he became capable of sometimes turning on the charm for the crowd. Most people still are not privy to it but it is because most of the time he just doesn't care.

Best of luck to everyone struggling with this.