You have launched the instance in VPC. Here is the check list:
- When launching the instances in VPC, make sure you launch it in the public subnet of your VPC. Else it will not be accessible from outside
- When launching the instances in VPC (presuming public Subnet), do ensure that you check a box which says something like "assign a public IP address to the instance" at the time of creating the instance. By default this is not checked. So if you fail to check this box, then Instance will not have a public host name. You can however, assign an elastic IP later on.
- Make sure you VPC security groups are configured properly to allow necessary incoming/outgoing access. In your case, incoming access on port 80 is/443 is essential.