Banodoco Discord is ground zero for AI film and focuses on open source models and resources. Their results are a year ahead of SOTA models as a result of their workflows and effort.

https://banodoco.ai/

Invoke AI has incredible open source image editing tooling and a fantastic YouTube and Discord that pair with it.

https://youtube.com/@invokeai

Curious Refuge (paid) has a great community and paid lessons for AI filmmaking.

https://curiousrefuge.com/

Reddit is overflowing with AI art communities, many of them technical in nature.

https://www.reddit.com/r/comfyui/

https://www.reddit.com/r/StableDiffusion/

There are a lot of offshoots of these, and Discord will provide the best resources once you get plugged in.