Azure Stack Portal

The most general way to use Azure Stack is the Portal. This is the UI and it provides more than 95 percent of all features, including RBAC. Depending on whether you are an administrator or a generic user, you will have different features available in the portal, but you always use the same portal.

The portal looks like this after a new installation:

As you can see, the portal looks almost exactly like Azure's and provides the same usability. It's quite easy and intuitive to use from the end user's perspective. You don't need to train your users in general, they could just start with the same experience they hopefully already have from Azure.