The Book of Numbers is a law book in the Old Testament section of the Bible. But the Book of Numbers is also a history book. It is the story of the people whom Moses led through the desert. Moses counted the people in Numbers 1 and Numbers 26.
The people did not always obey God. They complained about the food in the desert (Numbers 11 and Numbers 21). They refused to enter the land that God had promised to them (Numbers 13). They even wanted to return to Egypt (Numbers 14). This is why they were in the desert for 40 years.
The Book of Numbers also tells the story of Balaam. Balaam was a foreign prophet (holy man). Balaam intended to announce an evil fate for the people. But instead, Balaam saw that God was with them.
Balaam spoke only the words that God wanted him to say. So, Balaam blessed the people (Numbers chapters 22-24).