The child theme should be installed automatically during the setup wizard. If you missed this step, you can find it in your theme folder tethys/themes/tethys-child/
Thanks, I just installed it and indeed the child theme could be installed during the process.
I’ve installed all dummy content. When I change something in the theme settings, nothing changes on frontend. For example hide the social links, making the product image larger and hide the add to cart input selector. Did I miss something, because the settings does not seem to work?