When following the signup wizard, a Hub will be created automatically by the time the portal is reached. However, it may be helpful to create a sandbox hub to follow along with this tutorial.
In the portal, navigate to the left-side navigation menu above the search bar, and click the caret next to the current hub.
This action opens the Hubs dialog, where the Create Hub button is visible in the top right. Click the Create Hub button.
Next, name the hub and click Create.
The portal will automatically navigate to the newly created hub.