This passage begins with a powerful reversing of the exodus. They have just crossed the Jordan, made dry by God, and now they restore the tradition of circumcision. Then they celebrate Passover; then the manna from heaven stops--because they don't need it anymore.
Then there is the battle for Jericho. The battle is a cool narrative about obedience to God, courage in the face of danger and having faith in a miracle. It also contains details of killing every man, woman and child inside of the city except the Prostitute Rahab. (btw, it's not clear to me how the Israelites felt about prostitution in general. I know a Levites daughter can't be a prostitute, but that sort of begs the question about who can be a prostitute.)
The need for obedience is emphasized further with the story of Achor. He hid some spoils of war and brought them back. Because of this person's disobedience, God turns his back on the Israelites and they loses what should be an easy battle. Achor is stoned to death, which explains the big pile of stones still there to this day. These passages, as I recall, are littered with "which is still there to this day" type stories.
Don't worry, they rally and go back to destroy Ai. The passage ends with Joshua restoring the covenant to Mount Ebal and writing the blessing and curses that Moses told him too.