1) Get going.
2) Be strong and courageous because I am with you.
3) Don't forget all the stuff I talked to Moses about.
But there is a depth here that is worth mentioning. This is the people's GPS, God Positioning System. So when people question 'where are we going? are we there yet? where is God?" Joshua will be strengthened and shaped by accessing God's presence, like Moses. Or when the people say "Moses wouldn't have done it this way. That's not what we did when we were in Marah." Joshua is not leading the way and he will need to be clear about his direction. That direction comes from accessing God