Encyclopedia Beitannica:
“As a branch of Christianity, Roman Catholicism can be traced to the life and teachings of Jesus Christ in Roman-occupied Jewish Palestine about 30 CE. According to Roman Catholic teaching, each of the sacraments was instituted by Christ himself. Roman Catholicism also holds that Jesus established his disciple St. Peter as the first pope of the nascent church (Matthew 16:18). Centuries of tradition, theological debates, and the wiles of history have shaped Roman Catholicism into what it is today.”
Yes. All kinds of syncretic pagan practices were added - many from Greek religion and some just made up.
But this is America. Believe and practice as you wish.