Tbh that sounds harder than just learning CAD, which is really not that difficult if you use a proper parametric editor - I would recommend SOLIDWORKS first. It's got the easiest UX so is ideal for learning. They actually have a vaguely reasonably priced subscription now, but IMO it's still way too much for occasional hobby use so I'd recommend just pirating it (which is easy).
Once you have learnt a bit then the only FOSS options that are worth a damn are a) SolveSpace which is quite good and light, has a slightly quirky UI (but not in a bad way) but unfortunately has some critical missing features at the moment - notably bevels/chamfers. Although I did see someone made a sloppy PR to add them so we'll see where that goes.
Or b) FreeCAD which is actually good now and fairly close to SOLIDWORKS (at least for the basic stuff you're likely to use) and has a reasonably good UX. Some rough edges still but overall it's very usable. Good enough that I reach for it instead of pirating SOLIDWORKS these days.
The basic workflow is pretty simple:
1. Make some planes, referenced from existing geometry. 2. Make sketches on the planes. 3. Extrude/revolve them (either adding or subtracting from the existing geometry). 4. Repeat until you have the right shape. 5. Add a load of chamfers to make it pretty.
From my experience people who heavily rely on LLMs are allergic to learning anything new (with the exception of learning new and improved ways to generate slop). They just 'want to get stuff done', even if it means staying in a local maximum forever.