Setting up access rights by territory

Hello,

I am using Microsoft Dynamics CRM for Office 365 package. Our company has created different territories (Europe, USA, etc.) which we use to categorize our customer accounts. We have different sales managers for different territories, and we would like to restrict their access so that each sales manager can only view the accounts / opportunities / reports / etc. associated with their own territory. I have not been able to create these access rights myself by reading tutorials/watching videos, so any tips would be greatly appreciated!

BR, Tomas