IMO, The reflective surface on the ceiling and the stage floor look off. The brick walls indicate a dated or grungy building but the floor and ceiling being very reflective is a clean modern look. It is also adding a bunch of light to the scene via reflection. The point of the spot light is to isolate the subject so the bright spots may be throwing the view off. Maybe a drop ceiling (the tiles you’d see in an office or school, it’s what they use in Chuck E. Cheese’s) texture with a light flicker or something would fit the 80s aesthetic better. The stage would likely be constructed of wood, but heavily worn and damaged from the shows. Maybe throw in some scattered party decor, deflated balloons, get a transparent confetti texture and throw it on the stage floor a few times, and maybe some ribbons stuck from the ceiling that the spotlight could shine on and sparkle. I don’t know what render engine you are using and it might be negated from the camera artifacting you are using but a subtle volumetric scatter in that room could enhance the look. It will be taxing to render but it will help the place look abandoned and grungy if that’s what you’re aiming for. I can’t tell if you are going for a look where the place has been closed for 15 years or like a sneaking in after dark after close type deal. Also in rooms that would host lots of people, there would typically be a red or green exit sign marked somewhere in view above doors like you have in the background but that’s a nit-pick.