It is normal to see that error on a new install until data is created no siteSettings can be loaded.
Please specify db and OS you are using
What do you see when you go to /Setup/Default.aspx?
What do you see if you go to /Setup/Upgrade.aspx?
Try in web.config change
ShowConnectionErrorOnSetup = true
and
ShowHistoryOnUpgradePage = true
and see if any better info is shown on those pages.
Hope it helps,
Joe