CDP provisions EC2 instances as part of environment creation process (for data lake and FreeIPA) and for compute clusters.
Therefore, you should verify the limits on the number and type of EC2 instances in your AWS account to ensure that you are able to create clusters in CDP.
CDP provides default AMIs that are used for data lake, IPA, and compute cluster instances. In case of Data Hub, you can optionally create and register your own AMIs. The AMIs provided by default for Data Hub are pre-warmed images (i.e. with Cloudera Runtime and Cloudera Manager pre installed). If you would like to create your own AMIs, you can use the base image to create a new one. Currently, CDP supports CentOS 7 only.