From the Sites screen you can view the consumption and usage information, start or stop your Trial system, scale it up or down, scale it in or out.
Sites page is not a monitoring tool and its features are unrelated to Teradata Viewpoint. Although current Teradata customers may have access to Viewpoint to monitor and manage Teradata Vantage systems, Viewpoint is not included in Vantage Trial and you cannot use your own Viewpoint instance in Vantage Trial.