Thanks Paul. Using joomla for several months, and just getting into joomshaper template application.
The copy template button action did create a new folder (copyofnewsberg) in the templates area, but understand that sp page builder additions would not have been copied, nor custom css.
Currently my customized css is in the helix template options custom code area, and I do not see a custom.css file, so that helix-entered custom css code is presumably in the database.
My intent was to preserve a copy of the template within the joomla environment before I began making further modifications, in hopes I could "switch back and forth" between an original working template and one I'm editing. I can make backups of the database and web site as needed, and was just seeking to have a preserved "original copy" of the template within same joomla environment as template undergoing modifiction, for comparsion purposes, and thought the Copy Template button would achieve that, and seems due to internal naming aspects this may not be achievable in that manner.