Hi@akhtar,
After creating a VPC you need to create a subnet so that you can launch instances into that subnet. You can see the below code to create a subnet.
# create subnet and associate it with route table
subnet = ec2.create_subnet(CidrBlock='172.16.1.0/24', VpcId=vpc.id)
routetable.associate_with_subnet(SubnetId=subnet.id)