1. Run Microsoft Azure Active Directory Module for Windows PowerShell as administrator.
2. Connect to O365 by using the following scripts.
Install-Module -Name AzureAD
#Log-in using your global administrator account (Other roles can also be used).
(Get-MsolUser -UserPrincipalName firstname.lastname@example.org).Licenses.ServiceStatus
# This will return a list of SKUs that are enabled to the user’s account
If you are thinking of familiarizing all SKUs in Office 365 licenses, check this document: