How do I restore documents and desktop from iCloud?

I'm not sure what I have done but in Finder my Documents folder and Desktop folder are sitting in iCloud and no longer on my physical MacBook Air. When I go to Finder and select my User folder these two folders are whited out. Now I am getting a warning that my iCloud is full and to upgrade. Please help. I'm sure it is a simple action but I'm scared to try anything in case I cause a bigger problem. TIA.

[Re-Titled By Moderator]