Documents moved - to cloud?- on Mac Air

This morning turn on my Mac Air and all of my documents (lots!) have been moved to, I think, iCloud. My familiar "Documents" location does not appear in Finder. In Finder, it looks my entire laptop moved to being listed in "Locations" (But I still can't get to my documents through that). Finder is also showing the names of old files from my old laptop that are not actually saved on this laptop. This is very frustrating. How do I get my docs back to my laptop? Or, if thats not the problem, how do make them to easier to find? And why in the world did just happen? Even if it was an update, why would an update do something like this???