The Blackmagic Camera Facebook Group, with 56,000 members, is very active. There's also a Group with 42,000 members that's specific to the Pocket 4K and 6K cameras. In addition, there's a DaVinci Resolve Group.
I'd suggest that you also check out
https://cinematography.net, which is probably the longest running cinematography forum. See the "Discussions" section in particular.