Developing neighborhood connectivity, trust, and belonging is essential for the mental health of young people. Social connections help mitigate the stressors young people face. Technologies that build community engagement and include information of public and local interest, that is, civic technologies, have shown promise for improving social connections. Yet existing tools often fail to sustain public interest or help the public intuitively navigate the complex data displayed, and also often lack transparency. Little is known about how civic technologies can be designed to engage young people, whose ideas about what community means and how it is best formed, often differ from the adult-centered views driving existing tools. Addressing these research gaps, the project team is creating and evaluating a toolkit that will include a novel suite of data and technology to support youth-led civic engagement, build a more socially cohesive community, and in turn support youth mental health and the wellbeing of people in the local community. Through collaborations with community and municipal organizations, this work is improving civic data access for youth and their communities, enabling community-grounded data interactions that advance social cohesion and wellbeing, and helping build data literacy, an essential 21st century skill. This research is engaging youth in the co-design of a toolkit and activities for building data literacy, software tools for community data collection,