Early farmers didn't have tools, they planted and harvested with their hands.
Soon, they learned how to make tools like hoes and plows.
The new tools led to an increase in wheat production, or a surplus.
Now, not everyone had to be a farmer. People could specialize in crafts like carving, making pottery, or trading.
Because of the extra food, families could now afford to grow, so there was a population increase. They started building permanent homes because there were now enough resources in one spot to bother to stay.
Now that there was a larger population, tiny villages and towns grew larger, and expanded into cities.