I know we'd all like some scientific actualisation of Star Wars but I mean:

• They made noise in space 'cause that's fun.
• There was always gravity on pretty much any ship.
• I don't really recall any spacewalks so we don't see any instance of 'no gravity'
• There's hyperspace since lightyears is a bit of a long time.
• Stormtroopers seem very scientifically and inefficiently accurate

At this point I think the Star Wars movies (the oldies) pretty much ignored a fair bit of the science.

But if it was a death star literally put there in our universe, I think there would be a bit of structural considerations for gravity, but not huge due to it being quite hollow. Gravity is pretty strong when the sphere is entirely comprised of dense rock and no air. A mostly hollow sphere of air where air is something close to 1/1000 that of rock (yes, used the density of water lol) is not going to get much of a rollicking from gravity.

Edit: an interesting 'expose' on the moon landings claim one thing: why were the photos so relatively boring? Because they were real and that's all they could get for all the limited resources they had at the time.