I think the first things we'll really make in space will be super structures and pressure vessels because those are the simplest things to make and the materials don't require a massive supply chain. We could even gain a lot just by lifting up generic stock from Earth (metal powders, sheet stock that could be formed into tubes, or just a lot of generic tube stock [1]) and learning how to assemble them via machine in space. It would let us build larger stations or telescopes than we could launch from the ground.
For example if we build a super structure in space we could launch a lot of large inflatable modules to fill it in with that would be mechanically simpler and lighter because they don't have to bear and transmit the thrust force just support their own mass under thrust.
[0] Which increases the amount of benefit needed to justify redesigning an entire chip fab for example to function in zero-G.
[1] Though lifting tubes has the problem that there's a lot of wasted space in a stack of tubes which is one of the problems we're trying to avoid by building vehicles in space to begin with.