How many maximum users can be added to Azure AAD?

I currently have an Azure account and use B2C. I can add users to B2C but it is missing the feature of Groups. The Groups are available in AD.

I have the following questions:

1. How many total users or groups I can add to AAD? The pricing chart in the following link does not specify it in the Azure Free tier. The link is https://www.microsoft.com/en-us/security/business/identity-access/azure-active-directory-pricing?rtc=1