The NPC villages can appear on most planet types, except for a few like Lush/Garden, Barren, Toxic and a couple others depending on the race. You can find one of their villages(Or in case of the Humans, their campsites)and do quests for the NPCs there until one offers to join you, or you could invite specific tenants into your Colony/Colonies and do quests for them until they want to join. There are a couple different ways you can recruit someone for your space crew. The seven races are the ape like Apex, the bird like Avian, the plant people Floran, the robots of the Glitch, the ole basic Human, the amphibious Hylotl, and finally the beings of energy the Novakid.
They don't all need to have been there at the same time, as long as you've had that race recruited at some point, it will count, even if you dismissed them after. As the achievement says, for this one you'll need to have recruited at least one of each playable races in the game in your spaceship crew at some point.
