Upgrading to Sierra on MacBook Pro opened macOS Utilities?
It seems like your Mac is booted into the Recovery partition. Shut it down and try to boot it normally - it may not have upgraded at all. Then try the install again. If you have updates for your question, edit your question to add them and then comment on this answer so I notice.

To answer a few of the other questions you had:


I would expect an error message to stick around, so you probably didn't miss one.
I doubt permissions would be an issue as you didn't see an error message.
If upgrading to Sierra was not supported, you probably wouldn't have been able to start the install.
You can almost certainly fix this yourself! Also, the Apple Store may not charge you for this, so it could certainly be worth stopping by.