Start at the beginning why not? The earliest writings are mainly letters but they give a fascinating insight into the church. Those of the generation of Polycarp, such as Ignatius were actually taught by the apostles, indeed refer to such as Paul.
See here for example
EPISTLES
Take just one letter ignatius to the smyrneans (polycarps diocese) (two paragraphs below)
Which confirms belief that the eucharist is the flesh...and it is heresy to think otherwise.
That to be valid it must be performed by a bishop.
I enclose a couple of paragraphs below -
RCC did not invent this stuff. The early church was liturgical (eg didache) sacramental, bishops and so on, as demonstrated by what the fathers say, and they were taught by the apostles..
So irenaus, ignatius, polycarp , justin martyr are some of the first. Later fathers, the sermons too are fascinating, explaining links between OT and NT in ways few consider.
CHAPTER VII.--LET US STAND ALOOF FROM SUCH HERETICS.
They abstain from the Eucharist and from prayer, because they confess not the Eucharist to be the flesh of our Saviour Jesus Christ, which suffered for our sins, and which the Father, of His goodness, raised up again. Those, therefore, who speak against this gift of God, incur death in the midst of their disputes. But it were better for them to treat it with respect, that they also might rise again. It is fitting, therefore, that ye should keep aloof from such persons, and not to speak of them either in private or in public, but to give heed to the prophets, and above all, to the Gospel, in which the passion [of Christ] has been revealed to us, and the resurrection has been fully proved. But avoid all divisions, as the beginning of evils.
CHAPTER VIII.--LET NOTHING BE DONE WITHOUT THE BISHOP.
See that ye all follow the bishop, even as Jesus Christ does the Father, and the presbytery as ye would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is [administered] either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church. It is not lawful without the bishop either to baptize or to celebrate a love-feast; but whatsoever he shall approve of, that is also pleasing to God, so that everything that is done may be secure and valid.
I have to go for a few days. God bless all.