This challenge is pretty easy. What you have to do is build a mini-town or a building on one lot that contains all requirements for all community lots.
You can make a city in a building, like the town of Whittier in Alaska or a mini city, it can be inspired by a real-life city or you build however you like it.
For an extra challenge you could try to do it on a small lot.
I would like you to suggest any improvements, if there are any.
I hope to see your creations.