About CloudFormation Templates – Refer AWS CloudFormation Templates
There are AMI’s which has Wordpress pre-installed.
Ex: WordPress powered by Bitnami. Wordpress has lot of website templates.
Joomla – Joomla! powered by Bitnami
If you are looking to host a static website using AWS S3, you can refer
Hosting a Static Website on Amazon S3
Hosting a Static Website on Amazon Web Services