First, make sure that you are in the Edit mode of the Layouts pop-over (this means that Edit does not appear in the upper left of the pop-over).
If the select option is not available for a Layout (empty circle doesn't appear to the left of the Layout), that means that you are currently in that Layout and it is "active". It is not possible to select "active" layouts to copy or delete.
To make the Layout available for copying or deletion, select Done to exit the Edit mode then select a different Layout. Once in a different Layout, select Edit and your desired Layout should no longer be "active" and now be available for selection.