I recommend trying to reach put to large organizations that align with your interests in this case.
Especifismo: black rose anarchist federation
Radical unionism: Industrial Workers of the World
Both of those orgs will be able to help a lot more than we can, if you want to build something aligned to them. Building different organizations take different approaches, and they can share their experiences and strategies that are more likely to succeed.
I’m not from the US, so I don’t know many more organizations. But the principle stays the same: you want to build a mutual aid network, try talking with people already working on those, even if they aren’t from the same place.
Now, as to what exactly amongst each of those you should do, I think only you can answer. My approach is that the best thing is something that touches you (be either in your heart, your body or your wallet). So basically, what do you feel like doing?
I wish you the best of luck, comrade :)
Russian repression is so fucked up