First you have to learn the basics of PowerShell and once you know it, you can use Azure PowerShell commands, tweak them and use code for automation or administration
I have heard of Learning PowerShell in a Month of lunches book and also YouTube channel. They should be good enough to get started.
When I was new to PS, I have gone through Channel9 videos given below. Later I practiced running Azure PowerShell commands. https://channel9.msdn.com/Series/GetStartedPowerShell3
Please don't forget to Accept Answer and Up-vote if the response helped -- Vaibhav