I REGISTERED BUT I CANNOT CREATE VMS.

The "Usage" tab allows you to check out the state of all your resources on ~okeanos-knossos. Resources are granted through Projects and have a limited duration. The default Project for your account is named "System project". If you are a new user, you won't be able to create a VM, because the quotas of your System project are set to 0. You should gain resources though by joining an existing project or creating a new one.

You can find more information in the relevant policy page.