But I can't tell where the openings are. I can't even tell for sure if this is a top-view drawing.
Or do you mean the walk-ways? If so, then your proposed interior room is longer left to right, yes? In that case you'll set up facing the left wall.
Maybe these articles and videos will help you:
How to set up a room Maximum Studio, Minimum Stress Room Setup The Ultimate Home Studio
--Ethan