As the Network Admin user you will be able to see all the Firms who have access to use EVPro and be able to edit their ability to see/use the Modules that you've purchased.
It will look something like this, depending on the Modules that have been purchased:
Any firm attached to your Network will inherit the purchased Modules. Simply untick items that the firm should not have access to.
You will also have access to the Users from the Network and again be able to edit their ability to see/use each Module and their access to the different areas within Settings.