Setting up Portal Trial in Dynamics 365

Create your dynamics 365 trial as a first step (if not already created)

https://signup.microsoft.com/Signup?OfferId=bd569279-37f5-4f5c-99d0-425873bb9a4b&dl=DYN365_ENTERPRISE_PLAN1&Culture=en-us&Country=us&ali=1

Once trial is set up successfully, open the admin center for Dynamics 365 and select Applications and click on Manage to configure the portal.

Provide details for the portal

Click on Accept

Grant Permission to the Portal

We’d get the below message

After some time

Clicking on here takes us to the manage your solutions page

Once configured we’d see the following area\groups\sub groups added to site map specific to portals

Portal : 

Hope it helps..