Historians from the time period and Roman records from the time period mention the existence of Jesus with no dispute as to if he really existed. This isn't iron clad evidence that Jesus existed. That is there is iron clad evidence that there were people named Jesus at the time but that doesn't tell you if anything else from the story is true. The historians and Roman records admit that there almost certainly was a Jesus that was crucified. They also provide evidence that the claims made about Jesus, insofar as they touch on Jewish and Roman law and the facts of the trial, are not contradicted. This means there almost certainly was someone (well, at least one) named Jesus that was crucified by the Romans at the request of the the Jewish authorities and that this person claimed to be the Messiah.

Again given that Jesus was a common name, crucifixion was not uncommon, and Jesus in the Bible takes the place of someone else that claimed to be the Messiah then this still isn't saying much. In particular it doesn't say anything about any teachings of said Jesus or anything on the miracles or the resurrection. There is, as far as I know, no non-partisan record of any of those things.