The first step must be to acknowledge that there is nothing about Jesus up until around the years 80~120. That simple FACT is uncontested by everybody, and it is also the only fact uncontested by everybody. That is nothing controversial, yet somehow here everyone that brings it up gets downvoted.
Most of the "evidence" is from the second century onwards and written only by christians. You would need to go a couple of centuries forward to find real third-party references about him. Most historians consider this as proof of existence of a person 100 years earlier, that is also true. But I don't know why christians clench so tightly around historians on this issue, when it is also the opinion of most historians that the accounts about Jesus are not historical, and that most of the events told about him historically never happened.
So, if we are gonna go with historians on this, then:
1) Jesus was a real person.
2) Nothing in the new testament about Jesus can be said to have happened except that he was born, that he was poor, and that he was crucified.