I’ve always heard that we are almost certain Jesus existed as at least some dude who lived at that time. What else is commonly assumed as something that happened?
More can be said about specific events if anyone has deeper knowledge, but the FAQ does cover this a bit. I'd point you to two answers:
Is the Bible/religious texts considered a reliable source for historians? by /u/kookingpot
Is the Bible a historical book and if it is does that mean it is historical evidence for the existence of Jesus? by /u/talondearg