I would not call the first century Christians Catholic. They were simple christians.
I think Catholicism began when the roman empire adopted the christian religion as an official religion.
Maybe the Catholics claim that they started with Peter, but I am sure Peter had nothing to do with them and / or their believes.
I think the claim of the catholic church that they started with Peter or that Peter is their founder is similar with the claim that JW's make that Jesus is their head or that Jesus is guiding them from heaven.