Paulie was a soldier in Tony's dad's crew.
Silvio has been a family friend, associate and possibly soldier since the early days as well, having ran clubs before the Bing.
Eugene (the rat) and Tony played on the same sports team when they were young.
Christopher, of course, grew up with Tony and was like a little brother, as Tony watched over him when Chris' dad Dickie was murdered.
Ralphie was a young hoodlum with Tony in the days before they became made guys.
Bobby's dad was a soldier under Boss DiMeo and probably had been in Junior's crew, since it is Bobby who takes care of Junior in his old age. Tony's dad had been a soldier and then captain. So both Tony and Bobby grew up in the business and likely acquaintances.
Vito was related by marriage to Jackie Aprile Sr. and cousin to Jackie Jr. (who he later whacks).
Carlo, Patsy or any of the others? I don't know the backstories.

Carlo went back to the Family at least as far as the late 70s (Paulie mentions a vacation that he, Tony, Carlo and some others went on in 1978).
Ralphie, Tony, Silvio, and Jackie, Sr were all part of a little crew together as teenagers. Jackie probably got involved because his brother Richie was a feared Capo.
Big Pussy was a soldier in Johnny Boy's crew, with Paulie and when Johnny died, Tony inherited both of them.

The pilot was filmed in 1995 I believe, 4 years before it was released.

"considering what happened in the pilot as canon" is a terrible idea.

The Pilot was filmed like an year before the rest of the first season, and among others, that very line you mentioned is totally out of sync with the rest of the series. it implies that Tony and Artie hadn't been in touch for years but it was later established that Artie was Tony's one big friend outside the "life" and Silvio would have to know him way better than "some guy named Artie Bucco".