Google Cloud Shell has been disabled for my account.But,I didn't violate any term of services.I am beginner in python.I am developing some scripts based network libraries and threading such as scanning networks.How I can get help to solve this problem and If not,Can I download my files in cloud shell?
There's nothing Stack Overflow community could do with your ban of using Google Cloud Shell. Reasons for such restriction you can find in notification (probably via email) from Google Cloud.
To solve this issue you should follow instructions received in the message from Google.
As you can find in the documentation Cloud Shell is a managed by Google interactive shell environment for Google Cloud Platform:
Cloud Shell provides command-line access to the virtual machine instance in a terminal window that opens in the Google Cloud Console.
also, at Configuring Cloud Shell:
Cloud Shell provisions 5 GB of free persistent disk storage mounted as your
$HOMEdirectory. All files you store in your home directory, including installed software, scripts and user configuration files...
So, your files accessible only via Cloud Shell and you should contact Google Cloud Support to reach them.