Start a 'Tiny WPA' project in your community and use ioby.org* to connect with local resources and volunteers. Tiny WPA is a program that empowers young people to design and build improvements to the public spaces, schools, and micro-infrastructure in their neighborhoods.
Before you start, download Frog Design's "collective action toolkit." The goal of the kit is to help communities generate solutions, connect to resources, and pool knowledge to solve challenges and create real change.
*ioby is a crowd-resourcing platform for citizen-led neighbor-funded projects.