Well I don’t know the complete answer, but I believe they had a Praenomen (pre-name= given name) and a nomen (name= family name). I don’t think they originally used cognomina (descriptive, epithetic surnames), but then again neither did the Romans originally.

As for the actual names themselves they seemed to be linguistically similar, but that may simply be due to the fact that I have read primarily Roman sources (such as Livius), and the Romans tended to “Latinize” everything.

I don’t know of written accounts left by the Samnites, meaning we have to rely on Roman sources, so I don’t think much can be known about their language.