Peter personally pastored the church that is in Rome, until he was murdered/unjustly executed by Nero. He was the chief of the Apostles, to whom Christ said that He'd give 'the keys.' When Peter died, his pastorate did not die with him, but he was succeeded in his office, by Linus, the second Pope/supreme pastor of the one Church.
A thing that the Catholic Church herself acknowledges.
All of them who believe that Christ Jesus is risen from the dead, are.
Peter may have been at Rome. It is the traditional story, but there is no information in the Bible to prove your claim. If Peter actually was at Rome, he would have evangelized and taught others. That does not mean he was an elder or a bishop in Rome. Again, that claim you make is unsubstantiated story made-up by your denomination.
Second, your church butchers Jesus comment where Jesus says "I am the ROCK, you (Peter) are a rock with which I will build my church." Peter, like everyone in the body of Christ is one of the rocks that make up God's elect.
The papacy didn't come into existence until the Roman government took over the Roman church and the leader took the same Latin phrase that the Ceasars had claimed as a spokesman for the gods. That was nearly 400 years after Peter died. Therefore Peter was never a Pope. In addition, we know that Peter was married so he never met the celibacy rules that Rome demands.
Please, research this history outside of the propaganda you have swallowed.