Okay, so you don't believe in representational democracy.
Nope. Relying on political operatives to faithfully represent our interests is how we got into this mess in the first place.
I'm not surprised that if you can't be bothered to vote then you can't be bothered to influence who you get to vote for.
I already voted. I'm just not pretending that we get to have any influence over who we get to vote for.
What's a realistic way to build these alternative structures?
Follow a historical example like the Black Panthers. If your community has an unmet need, serve it and use it as an opportunity to organize your neighbors.
How do these alternative structures work such that your local needs are met and the genocide in Palestine gets stopped?
Nothing threatens the structure of power more than the existence of organized groups of people who don't depend on it.