There are no planets or moons in the solar system that is "habitable". One that has all the things we need to survive in. Mars and Luna has the rudimentary structures that is needed to construct the settlements in lava tubes, but these structures have to be built using advance building techniques and materials. Like building a modern subway system, we don't expect a transit system to naturally occurred on Earth. We have to take what is there and build upon it so it can be breathable and sustainable. Where we can grow food and raise our children. When the settlements of Luna has explores, scientists, students, and restaurant workers; then we can truly call ourselves a space-faring civilization. When we have resources management from all of the planets/moons. then we can see the future looks bright; so we gotta wear shades.