There is testimony from eyewitness and from people who interviewed the eyewitness, both in the New testament canon and outside it, about Jesus of Nazareth.
Roman, Jewish, Greek, Syrian historians of the first and second centuries accepted the historicity of Jesus of Nazareth. These weren't all stupid, gullible people. Historians are people who check the reliability of sources.
The are no known accounts from antiquity I am aware of from this time period which claims Jesus was a fabrication and never existed. Even the Jewish Talmud seems to acknowledge a historical Jesus who was crucified. If anyone had incentive to claim Jesus wasn't real, that he was a fabrication it was the Jewish priests and scribes.
All the body of historical evidence points to the historicity of a rabbi called Jesus of Nazareth. There is no competing body of writing that claims Jesus was a fabrication. That has always been considered to be noteworthy.