Eureka! I found the theme editor, I see the CSS file; and other files, whew! I can start figuring from there.
Thanks for the tip on backup, a favorite thing of mine. I guess I need some basic orientation on that. Where do these files physically exist? Are they on my remote hosted server, or a WordPress server? Where are the files backed up to? I read something about a backup utility…is the main thing to start learning about?
I very much appreciate the help getting started.