If you copy something it goes into a buffer and stays there until you copy something else. Then that replaces the first item. I use Notes as a scratch pad to put stuff. Just open Notes, double tap on a page to bring up the paste option, tap on paste and now you have a copy.
In addition, when viewed in landscape, you can swipe right on a note in the left column. This will make a red "Delete" button appear so you can delete the post. If, in portrait mode, you press the button titled "Notes" (upper left), you can do the same thing within the drop-down list.