ok thank you, if it had worked out of the box, I would not have been googling for fixes.
after reinstalling and running docker version again, I get
CinemaTub:~ # docker run hello-world
docker: Error response from daemon: lstat /storage/.kodi/userdata/addon_data/service.system.docker/docker/overlay2/f6e18d25c96e24cbb4ba258a5d850b6a812c8c4d19f3ccfdd748088a810707ff: no such file or directory.
See 'docker run --help'.
I think I saw a post about having to run as the 'nobody' user, or granting permissions to folders, so I'll retrace the searches I've done for the past few days. Thanks again.