The Repopulation, you're not going to go down to the science fiction equivalent of Ikea and buy the Martin Plasma Rifle. You're going to get out into the wild and get the resources you need. There are two systems for gathering items in The Repopulation, and the newest development blog for the game discusses one of the ways to grab those resources: Extraction, also known as "digging useful components out of corpses."
Since the game doesn't feature levels, there's a more organic system to gathering these resources. Players first decide how difficult the extraction should be, with higher difficulties resulting in higher-grade resources. More difficult extractions take longer, however, and as a result, players have a higher chance to fail unless they've practiced harvesting a particular species. For more details on the specifics, check out the full development blog on the official site.