Hi Leon,
By default, Office 365 users can create up to 250 Office 365 Groups each. Office 365 admins have no limit on the number of Office 365 Groups that they can create. The default maximum number of Office 365 Groups that an Office 365 organization can have is currently 500,000, but can be increased by request.
Moreover, we can block all users in the tenant from creating Office 365 Groups, or allow the security group the ability to create Office 365 Groups. The number of group each user creates can't be set to just 2 or 3.
For the details, please refer to Manage Office 365 Group Creation
Thanks,
Felix