Colonizing any of the rocky bodies in the solar system has the problem that all of them have far lower gravity to that of earth, which has implications for the health and comfort of long-term inhabitants.

A more realistic model is to put a habitat in orbit around any body which has some kind of economic purpose, which can be spun to produce a comfortable 1g.

Then people can travel down to the surface to harvest the resources, or do so remotely. The orbital station is a more convenient platform for trade with Earth or other habitats. The resources could be stored on the planet itself if space is limited in orbit, and then only shipped up to orbit when a ship has docked ready to take the goods elsewhere. If there is some reason that processing the raw materials is better in low gravity, then the habitat might be larger and have facilities for doing that or it may be shipped to another habitat which specializes in such activities (say, over mars which is closer to earth and might have massive complexes of farms on the surface to support city-scale population living in orbit) before ultimately being taken on to Earth where it is ultimately turned into Useful Stuff. Earth in turn would supply these habitats with manufactured goods both practical and luxury as well as trained personnel and other benefits of it's vast population and long established infrastructure.

Eventually, habitats would start trading directly with each other too. And thus Mankind will Conquer Space.