There’s a significant number of them in my mutual aid group. You could try to see if there’s an existing group in your area-if you are having trouble finding one you could help out at a food kitchen for a while and keep an eye on who comes to donate food regularly or chart with other volunteers about other groups they may be a part of. You could also see if there’s a DSA (or similar for your country) chapter and ask some of them if they know any other groups that might be more in line with what you’re looking for.

At least in my mutual aid group a lot of people volunteer at multiple orgs from food kitchens, animal shelters, clothing upcyclers, bike repair, etc.

You could also try to arrange a book club for something like Dean Spade’s “Mutual Aid: Building Solidarity During This Crisis (and the Next).”