This is good advice. Each of us is a small force alone, but that force can be multiplied when we join forces with our comrades. In NY specifically, you may want to check out the Working Families Party: workingfamilies.org

They are represented on the ballot and typically endorse the more progressive Democratic candidates. They could have local resources to aid you with your protest and you may be able to gather additional protesters. You may also want to connect with your local mutual aid group as there are often politically progressive people involved with those.