The simplest thing is make friends with your neighbors. Once you have a bond with your neighborhood, you can become educated about local issues, and spread this knowledge among your community. Then the community can work collectively toward its interests.

Even if you live in a rich / sheltered community, you can still help your neighbors understand the needs of underprivileged communities and how they can help.

Finally, organize community engagement days. One day a week for you and your neighbors to clean up, attend a city council meeting, learn about current events, or vote in local elections. Or just have a mini block party for people to chat.