Just to piggyback on this topic, since it was so recent. (Thanks!)
I just installed the child theme (https://docs.generatepress.com/article/using-child-theme/), activated it, and when I go to the Appearance/Themes/Editor I’m still getting the “Heads Up” warning. I see the child CSS Style in the background. Should I need to add a funtions.php to the child theme folder for adding my functions? If so, what is required as a skeleton?