Josephus is one of the best-known of first century historians, but he was far from the only person who talked about Jesus in his writings.
What is really important to remember when you are talking to someone or even for yourself when you consider these various authors is that at this point you do not need to consider if Jesus is God or Savior. The important thing to know here is that Jesus was a historical person who lived when the Bible said he did and in the circumstances it describes.
Our faith is “historical and evidential” and this video (and please also look at the ones on “Voices from Church History”) will help you understand the historical part of it.