It doesn't matter when the word "Catholic" (which is an English word) was first used. As I wrote earlier, the word "Catholic" doesn't appear anywhere in the Bible. And it doesn't matter when the Bishop of Rome wrote something, as that term (or "Pope") isn't in the Bible either.
Additionally, Ireneaus' quote doesn't contain the word "Catholic" either.
"The history of the Eastern Orthodox Church is the formation, events, and transformation of the Eastern Orthodox Church through time. According to the Eastern Orthodox tradition, the history of the Eastern Orthodox Church is traced back to Jesus Christ and the Apostles. The Apostles appointed successors, known as bishops, and they in turn appointed other bishops in a process known as Apostolic succession." (source: wikipedia) So your statement "And as for the Orthodox Church, this was all long before Constantine, Constantinople, and the Orthodox" (which is redundant) has no value.
If any people can claim to be the originators of "the church" it is the Jews, since Jesus was a Jew, all the disciples were Jews, all the apostles were Jews, and Jews wrote the entire Bible -- both testaments -- with the sole exception of Luke.
In other words, the claim that the Catholic denomination was the first Christian denomination simply is not true.
Sorry, but it is true that the Catholic church was the first Christian denomination.
Second Temple Jews believed they were in a sacred covenant with God, which of course they were. They also held sacred their traditions and scripture, and had a High Priest in the temple in Jerusalem.
Catholics broke away from Judaism while claiming their church to be the fulfillment of Judaism, and the start of an incredible new covenant with all of humanity.
Catholics believe the covenant God held with only the Jews was now extended to include all of humanity. They continued, as their Jewish forefathers, to believe in sacred tradition, sacred scripture, and to have a high priest, now in Rome.
They taught and thought through a Jewish lens. Believed in the traditional Jewish scriptures, thought in Jewish ways, believed ancient Jewish prophecy had been fulfilled in Jesus.
For example, Isaac and Abraham, the great hinge that began the covenant with the Jews and God, was now seen as a prophecy of Christ. Isaac was not sacrificed, but the son of God was. Jesus was the son who gave up his life for love of humanity. Abraham could not find a perfect lamb to the sacrificed, only an old ram. This turned out to be a prophecy, which could only be fulfilled in Jesus, who was the perfect lamb.
Of course all the first Christians were Jews before they became Christians. But their belief that Jesus was God separated them from their parent Jews, and this was true almost from day one.
In the first two years after the crucifixion, Stephen was stoned to death. Also in the first two or three years after the crucifixion Paul was sent out to persecute Christians.
Jews did not persecute other Jews. As much as the Essenes loathed the priesthood in Jerusalem, they lived in peace with the Sadducees. Something very extreme must have changed for Jews to persecute other Jews.
It's obvious what that was. It was the belief that Jesus was God, which would be blasphemous to the fiercely monotheistic Second Temple Jews. If there was one concept that horrified Second Temple Jews, it was that Jesus was God and the equal of God the Father.
This was, in fact, the start of a new religion, which claimed to be the fulfillment of Judaism. The covenant which would now include all of humanity.