The Cloud9 workspace should be built by an IAM user with Administrator privileges, not the root account user. Please ensure you are logged in as an IAM user, not the root account user.
Select Create environment
Choose a name for your environment
Leave the default configuration and select Next step, we don’t need a heavy server for this workshop.
Lastly, select Create Environment
After a couple of minutes, your environment comes up. Close the welcome tab and lower work area, and opening a new terminal tab in the main work area.