Papias, writing early in the second century, said that
> Mark, companion of Peter, had written a life of Jesus, based on what Peter had told him.
> Matthew, the disciple, had published a collection of the sayings of Jesus in the original language.
That's it. There is no mention of four gospels until the second half of the second century (Tatian and Irenaeus).
If you look at the gospels attributed to Matthew and Luke, they both use most of the material in Mark, plus a common selection of Jesus's sayings, presumably translated from that collection made by the real Matthew. Matthew adds very little to that.
Matthew, Luke, and John all have awkward features suggestive of a late date. Matthew and Luke say Jesus was born in Bethlehem, despite being known as Jesus of Nazareth, because that's where the messiah was supposed to be born. The trouble is, that they give contradictory explanations, and that in Luke is historically impossible. Matthew and John were apostles, yet the gospels in their names never say "I" or "we". The real Luke was a friend of Paul, but Acts says Paul returned to Jerusalem after his vision, while Paul says he carried on to Damascus and didn't return for three years. And to cap it all, if you read John carefully, you'll see he has the crucifixion on Thursday instead of Friday!