Re: Child Theme Question from Super Noob
Try Arachnophilia from http://www.arachnoid.com/arachnophilia/
You can edit pretty much anything with it.
As for a child theme, here’s one way of thinking about it: the style.css file IS your child theme. Well, the skeleton anyway; the rest is muscle.
Like r-a-y says, just create the style.css file as per the instructions in the codex: https://codex.buddypress.org/how-to-guides/building-a-buddypress-child-theme/
You’ll need to enable the theme in Site Admin > Themes before you can activate it in Appearance > Themes though.