syncing folders and file storage between my MacBook Pro, my MacMini and iCloud

I'd like help syncing folders and file storage between my MacBook Pro, my MacMini and my iCloud account. I'd like all my files and folders to be duplicated on all three locations. As it is now my files and folders are spread out over these three locations, and it is very time consuming to locate my files on these three locations. Which folders cannot or should not be removed from "Favorites" ? Or how do I "remap" the existing default folders in Finder to always save new Downloads, Documents, Music and Movies to their respective folders with the iCloud folder in my Finder on my MacBook Pro, MacMini and iCloud account? Any help would be appreciated.