Sin has spread but God still loves humans. God plans to bring blessing to the world again, this would come through Abraham. God promised Abraham that he would have many descendants, they would live in some land that God gave them, and the world would be blessed through them.
Abraham did have many descendants, they ended up living in slavery in Egypt. this was not the land and life God had promised.
God got Moses to lead the people out of Egypt. Moses tried to persuade the Pharoah to let the people go. The Pharaoh wouldn't let them go so Moses put 10 Plagues on Egypt so that the Pharaoh would let them go. Waters to blood, frogs invade, dust turns to gnats and lice, swarms of flies, livestock gets sick and dies, boils breakout on the Egyptians, hail strikes down everything in the field, locusts devours every tree in the land, darkness covers the land for 3 days and the firstborn son of the family will die. Then the pharaoh let his people go after all these plagues.
God said to the people of Israel : I am the lord your God, the one who brought you out of Egypt when you were slaves. 1. Worship God only 2. Do not make idols 3. Don't misuse Gods name 4. rest on the seventh (sabbath) day 5. Respect your parents 6. Don't murder 7. Be faithful in marriage 8. Don't steal 9. Don't lie about others 10. Don't be jealous of others stuff. Those are the ten commandments that God gave the people of Israel.
Israel wanders and finds the land god promised them fairly quickly, but they don't want to go in. So they end up walking in the desert for 40 years. God decided that their children could have the promised land. So once they all die their children go and live in the promised land. The promised land is called Canaan.
Israel stopped worshipping God and started worshipping idols. God let enemies invade because Israel rejected him. When Israel suffered they prayed to god and God sent a judge to recue them. The judges led Israel to victory over their enemies. Israel lived in peace until the judge died then they started worshipping idols again. this keeps on going for centuries.