Storage ONTAP - Re–Assessing Allocation

Hello, 

So I'm currently new to the NetApp world and understanding the fundamentals of it.  I've created documentation but I'm stuck on a few task in regards to re–assessing allocation for .....

1. Deletion of unused storage (or a plan to delete) 
2. Re-Allocation of storage (or a plan to re-allocate)
3. Capacity Report 

Any info will be greatly appreciated, thank you.