(Including Nativity Trail, on water, crucifixion, and resurrection.)

I don't think you'll find any real answer. Some of the Gospels have different stories about things. For example, Jesus walking to Emmaus from the story in Luke 24:13-35, It's only in Luke, 7 miles or so. Would you count that mileage , did he walk back? Can't tell.

Many people walk some of his known walks for the experience. Perhaps that could be a goal of yours. Some of them are surprisingly unchanged, from what I've seen on TV documentaries.

You will never know the answer to ALL his miles of walking. Remember, he mostly walked to do his teachings. His other form of travel was limited to donkeys, I think.

Also, if you use the Bible for reference, the mile as a measure didn't exist then. So you would need to find out of your English version tried to translate into miles or what.

We have an account of him riding a donkey exactly once, the triumphal entry into Jerusalem. And that one was borrowed.

As far as we know He walked everywhere, and since we don't know all the places he went that aren't recorded, there's no way to tell except: a lot.