@akshay95 Because you are deploying this in Azure, you are already 1 level deep in nested virtualization. You should not need to re-install Hyper-V. Run the required commands, but go straight with an Ubuntu VM.
If you like, you can start with a Windows image first as a proof of concept before you try to deploy a Linux nested VM.
There are a few blogs on others who have done this, if you need help just let me know.