I am unable to find a product key to input into my computer to receive Windows 10 Enterprise.
With the subscription of Microsoft O365, there is NO product key for activation. Microsoft O365 is a new offering from Microsoft that combines Windows 10 with Office 365, and Enterprise Mobility and Security (EMS).
To install Windows 10, you need to login to Microsoft Portal (https://www.office.com) then check out the Microsoft 365 deployment advisor. For Windows 10 deployment, Microsoft 365 includes this fantastic deployment advisor that can walk you through the entire process of deploying Windows 10.