Have you tested the connection to the database? Look for the UDL file (normally in the HyperionFinancialManagement or Server Working Folder and 'Test Connection'
If this is successful, is the demo app installed ok? This is normally STAT, and set up by the tech who does the install. You do not say if you are installing or on an already installed environment.
Otherwise,
Are you using an ID with full Admin rights?
Have you spoken to Support? they can do a GoToAssist and check your specific settings - it does sound more like a Shared Services and permissions issue.
Good luck