Genesis 7 basically explains about the flood occured in the flood how it all happened. Noah was told to create a arc and to take animals pair so they could breed so they wouldn't go extinct. The animals were ordered to go into the arc by God. The animals got in the boat and the flood started and he flooded the world so he would kill all the people that have committed sins. He destroyed everything he had created because of sinners.
God created humans and he lost their trust. " Everything on dry land with the breath of life in it's nostrils died,"(Gn 7:22).
"For forty days and forty nights heavy rain poured down on the earth,"(Gn 7:12).
"Two by two, male and female came to Noah into the arc,"(Gn 7:9).