3 chapters. Pick a chapter, then pick a grade.
Joel 1 describes a terrible locust plague. What the swarming locust has left, the great locust has eaten. The vines, fig trees, grain and fields were ruined, and even the animals groaned. Joel told the people to tell their children about it, and called the priests and all the people to fast, gather at the house of Yahweh, and cry to Yahweh.
Joel 2 warns of the day of Yahweh like a mighty army. Then God calls: Yet even now, says Yahweh, turn to me with all your heart, and with fasting, and with weeping, and with mourning. Tear your heart and not your garments, and turn to Yahweh, your God; for he is gracious and merciful, slow to anger, and abundant in loving kindness. God promises: I will restore to you the years that the swarming locust has eaten. It will happen afterward, that I will pour out my Spirit on all flesh, and whoever will call on Yahweh's name shall be saved.
Joel 3 says God will gather the nations into the valley of Jehoshaphat and judge them for how they treated His people. Multitudes, multitudes in the valley of decision! Yahweh will roar from Zion, but Yahweh will be a refuge to his people. The book ends with blessing: the mountains will drop down sweet wine, and a fountain will flow out from Yahweh's house. But Judah will be inhabited forever.