Hi,
There is an issue with the code editor since Azure cloud shell was updated. What you can do is use nano editor instead. For example, in the exercise you can use below command instead:
nano HelloWorld.ps1
To save you can press Ctrl+S as mentioned in exercise, but then to exit the editor press Ctrl+X
Please click Accept Answer and upvote if the above was helpful. If something is unclear and/or something about nano is confusing, add a comment below and I will assist.
Thanks.
-TP