[Dylan Mercer]

looks like a lot of fractal clouds to me. The floor could be a circular 3D plane with fractal clouds applied.
The back wall could use CC cylinder:
•new layer,
•apply fractal noise,
•apply CC cylinder,
•set ‘render’ to ‘inside’,
•adjust z position so it fills the screen
•keyframe the y rotation.

That should get you close to the look. tweak it from there. hope that helped.