Someone said :
Perseverance rover has created oxygen on Mars with a lot of Moxie
(Mars Oxygen In-Situ Resource Utilization Experiment)
It used atmospheric CO2.
Is this the first step of Terraforming? Or are we more than 2 generations away of this even starting?
No, not even close, see it doesn't matter if they can build a small machine that can create 1 litre if oxygen using CO2 or a big one that can create a billion litres because the simple fact is we don't have the technology to get it there in the first place. Separating oxygen from CO2 is a relatively simple process, what's not easy is getting the 1 ton worth of machinery, that will be required to do it on a large enough scale to support 15 to 20 humans, off the ground in the first place and we don't have the technology to do that efficiently right now.
Currently the only viable option available to us would be to transport it to a space station orbiting Earth bit by bit and build it up there and then transport it to Mars but then you have to build a spaceship for that too so it's not really that big an achievement, it's pretty much putting the cart before the horse and it's a big fucking horse too.