How to manually save ONE file or folder to icloud but not have icloud automatically backing up every file or folder on my computer?

I want to use iCLOUD for 1 or 2 files but only for every files and folder.

To use icloud for files or folders i was told to go to APPLE> SYSTEM PREFERENCES>APPLEID> CLICK OPTIONS BESIDE CLOUD> and then check DESKTOP AND DOCUMENTS FOLDERS

But if i do that, will it AUTOMATICALLY save every file and folder on my computer to the ICLOUD or only the ones i manually select after?

I work at home so i want to backup my WORD file every day and then at the end of the month i want to delete them from the cloud.

So in summary my 3 questions are:

1. If i CHECK this box beside desktop and folders will it automatically backup all my files and folders? If yes, I don't want to do that.
2. If no, after i check that box do I then have to RIGHT CLICK the file i want to save to the cloud?
3. Can i delete my file or folders off the cloud?
4. OR can i LEAVE that box UNCHECKED and then just go to any file or folder on my computer and right click COPY and go to FINDER and in the left side bar just click ICLOUD and paste it into the downloads folder? Will that remain on the icloud? Is that the way to manually do it?

Thanks