Q: HELP…new iMac stuck during initial setup

I purchased a new iMac 27" today, and started going through the initial setup screens, including the wifi setup screen.  I got to the screen asking whether I wanted to upgrade to iCloud Drive, and I selected "Not Now", then clicked CONTINUE.  That was well over an hour ago, and the color wheel is still spinning.  Should it be taking this long?  I tried calling Apple Care but they're closed for the night.  I don't want to just shut it down without knowing if that will cause a problem.  Any suggestions?