Abraham and Sarah

we have been learning about Abraham and Sarah and how God gave them a baby by following Gods instructions. Before Abraham was called Abram and Sarah was called Sari. Abraham and Sarah were 40 years old and did not have a child but they wanted one then God said I will give you a child if you travel to the land of cannon and it will all be yours but Abram and Sari had doubt in God but they still did it they traveled to the land of cannon and then God gave them a baby boy.