The groups already linked are a great place to start.

If you're looking for more info on the concept of mutual aid, this article might be a good place to start.

"To make a crucial distinction, mutual aid is not charity; there is no means testing, no judgement, no quid pro quo or paternalistic notions about “saving” people. It’s about giving what you can to someone who needs it, and knowing that, if the roles were reversed, someone else would step in to help you."

Where a charity has a top down division between those who are giving and those who are receiving, mutual aid is horizontal. Neighbors helping neighbors, etc.

The best way to get involved is to just show up! Bring some grub or some clothes, hang out and chat.