From the letter it appears that in the beginning the Christians did gather on Sunday for a real feast, lots of food and too much drink. Everyone one would bring the equivalent of a picnic and have a great time. And as we read in his letter Paul put a stop to it. Why?
Because as we read,
When you meet in one place, then, it is not to eat the Lord’s supper, for in eating, each one goes ahead with his own supper, and one goes hungry while another gets drunk.
He then instructs them to get back to the foundation of the celebration of the Eucharist.
the Lord Jesus, on the night he was handed over, took bread and, after he had given thanks, broke it and said, “This is my Body that is for you. Do this in remembrance of me.” In the same way also the cup, after supper, saying, “This cup is the new covenant in my Blood. Do this, as often as you drink it, in remembrance of me.
It is from these words and the words of the gospel descriptions that the Church over time constructed the very simple Litrugy of the Eucharist that we celebrate in the Catholic Church. The elements: bread made only from flour and water, and unadulterated grape wine. In mass the Liturgy of the Eucharist is preceded by the Liturgy of the Word.
For those who wish Church looked more like a party or a rock concert, blame the Corinthians.