The answer will depend on what orgs are in your local area. If you’re willing to share a general location and any specific interests I could do some digging.
I don’t know anything about this site but I just found it by searching: https://www.mutualaidhub.org/
Or if you’d rather search on your own, I’d look for things like [your city/region] mutual aid, resist, antifa (the last one going to be about more confrontational action so consider whether that’s your specific niche).
Another approach is to just ask friends who seem politically connected if they’ve heard of any local orgs.
Personally I would be wary of any highly top-down orgs that enforce a particular narrow ideology. Some of these can be a bit cult-like. Also get a feel for how people interact and leadership operates. Are people supportive and kind to one another or is there a lot of tension and fear? Personally I haven’t had any bad experiences yet but it’s something to be aware of if you don’t have the lay of the land in your local area.
In most cities there will be a variety of groups with different approaches and focuses, so shop around a bit and find the one that is a good fit for you.
Since no one seems to be taking OP’s question seriously, I’ll take a stab at this. There are a variety of reasons.
Some people feel that voting is offering material support to a specific candidate or system, and they simply cannot bring themselves to do so given the horrors that that person or system is either supporting or failing to condemn.
Others may feel that strategically withholding their vote as a punishment may motivate democrats to take these types of issues more seriously in the future.
Or they may feel that their vote is more impactful in magnifying the voice and power of third parties who offer more meaningful solutions to end the killing, even if they won’t win.
Others still may believe that Trump’s incompetence will accelerate the end of America imperialism and lead to a better global political situation sometime in the future.
Finally, some people feel that voting won’t matter at all and is a distraction from efforts to directly slow or stop the war machine.
I don’t personally endorse any of these viewpoints, but some are relatively serious positions and others are not, in my opinion.