OK, never mind, I shouldn't have been here at all (but why was I sent here?). It was the "log in as Admin" link that I needed, but I had to discover this on my own by blundering around. This process is FAR too complicated for a new user.
I have the same issue. New installation. I need to select a theme for my site. The link sends me to a SitePad login page, black except for the working area in the middle. It requests an email address or a user name, plus a math problem to prove I'm not a robot. Every imaginable username or email...