Please disregard my previous post regarding selecting a page as the homepage for a group. I think I might have figured it out.

Part of the problem is that I had ” Is this tab visible to site admin only?” selected. That’s why it was saying that the page could not be found.

Triggering post moderation (3 links) so this is a private message.

https://codex.buddypress.org/administrator-guide/

https://codex.buddypress.org/buddypress-components-and-features/

https://codex.buddypress.org/getting-started/