Hello.
From my experience, installing Portal for ArcGIS is as simple as following the wizard. During installation, there is no 'software authorization' step like with ArcGIS Server. After installation completes, you will be redirected to a web browser to create a new Portal site. At this step, you can import the same Portal JSON file used in Production. Both tiers can have the same total allocations of each named user type and I recommend to my clients to keep both tiers with the same named user allocations. Staging cannot have more than Production.
The process to generate the json license file - Obtain a portal license file—Portal for ArcGIS | Documentation for ArcGIS Enterprise. While this process sets numbers against each named user, you need to import the json into Portal for these numbers to take effect.
Your My Esri account needs to be granted the correct privilege to create the license. These privileges are independent to your ArcGIS Enterprise\ArcGIS Online membership. Contact your organization's My Esri administrator as they can review your privileges and assign the licensing privileges.
I would contact your local Esri distributor's support team as they can provide more information on Portal membership and named user type allocations and help you with this set up\configuration.
Cheers Ed
