Does Cloud Shell creates any storage accounts and any other services in the backend if yes then does also cost for that on monthly or as per billing cycle in AWS?

Cloud Shell in AWS creates and manages the necessary infrastructure resources to provide you with a cloud-based shell environment. These resources may include compute instances, storage for your home directory and configurations, and networking resources. However, AWS does not charge you separately for using Cloud Shell.

As Stated by AWS here :- https://aws.amazon.com/cloudshell/pricing/ There is no additional charge for AWS CloudShell. You only pay for other AWS resources you use with CloudShell to create and run your applications. Additionally, there are no minimum fees and no required upfront commitments. Data transfer is billed at standard AWS data transfer rates.