Monitoring Computer / Storage / Consumption per Resource Group / Subscription

Hi. I am new to azure. 

We use Azure have have hundreds (if not thousands) resource groups. I need to run some analytics on these resource groups whereby i can see everything we have (hopefully something i can export into excel)

Is there such as way where i can easily determine how much compute / Storage is being used in my resource group and if possible the costs per resource group?

Basically, i need to find out a) What exactly exists per Resource Group, how much storage, compute consumption is it using. 

If this is not available out of the box, can anyone shed any light on how i can do something custom to obtain this info, maybe a powershell script i can run per resource group, or even subscription?

Thanks in advance