That part. Look at different forms of slang, cants, argot, etc. to see where etymologically they come from (IE historical context) and how they differ from the language. They’re if anything a form of dialect so it’s basically looking at your main language (English) and thinking about what words would change, how they would change, and why.
For example, workplace jargon is used to save time/effort when speaking to those on the same intellectual level as you (e.g. lots of technical terms rather than long explanations of what they do), there’s a lot of different slang words for drugs so that people can discreetly talk about them without alerting to others who aren’t in the know (e.g. marijuana: weed, green, veggies, Mary Jane). (Wish I could give you some reading material on this but we weren’t provided with any when I learned it D:)
I would also read up on some scifi books because I think many authors tend to insert some slang into these situations. In The 100 they use the word “croak” to say that someone is executed in space, in Alastair Reynolds’ Poseidon’s Wake there are a few words like gee (speed unit for space travel), holoship, skipover (to do with space travel); so I suppose it’s a mixture between technical language for space travel and engineering, and language to do with community and class differences.
Hope this helps!