The disciples were Jews and the first Christians were Jews. Maybe you should sit this one out.
Some were Jews.
We know from Paul’s epistles that Peter was based in Jerusalem and that he occasionally visited other cities as far away as Antioch and perhaps even went to Greece. Paul says that Peter was the apostle to the Jews, so he might also have visited Alexandria, in Egypt, and Cyprus, because of the large Jewish populations there, but we simply do not know.
A later tradition says that he went to Rome, and the apocryphal Acts of Peter, written around 150 to 200 CE, even says that Peter was crucified upside down in Rome. At the time Paul wrote his Epistle to the Romans, it appears that Peter had not visited Rome, so it is very likely that this tradition has no basis.
So Peter went around trying to convert Jews where Paul traveled to other places to recruit idiots who would believe such a wild story without proof. I can't believe they bought it. Even back then.