The tribes settling east of the Jordan return home, building an altar of witness on the way. Israel hears about it and gets ready to fight them, assuming it's an idolatrous altar. The tribes assure them they are loyal to God - the altar is not for another god or to sacrifice on at all, but for Israel to remember in the future that the eastern tribes are part of Israel, too.
Joshua charges the leaders to stay loyal to God, who has kept all His promises to them.
Joshua gathers all Israel and tells them their story, covenanting with them to serve God, not other gods around them. Joshua and Eleazar die and are buried in Canaan. The bones of Joseph are buried with Abraham, Issac and Jacob at Shechem.
How this is about Jesus
He ministers in Bethsaida a fair bit, which is east of the Jordan.
He leaves out none of the lost sheep of Israel.
He tells Israel their story, too, convicting them of hypocrisy and idolatry.
He is buried, but raised to life again.
Joshua ends with deaths and burials and charges to be faithful to God. There are already hints of disloyalty and idolatry coming in future generations, though. Note the futility: earthly resolve and warnings and charges cannot guarantee obedience - we still go astray and die.
Israel has rest, but not ultimate rest (Hebrews 3-4). Do not find your security in your own doings, deeds and works, but in God's.