Translation:Where is the room?
I think it might help to get a bit grammar-y here
です is a copula - it's used to describe what something is, its state. あります/います are used to say that something exists at all, but no more than that.
Here we have です, so you know the sentence is about some attribute of a specific thing - in this case, where that thing is located. (When you see です, you can sort of think that the sentence is basically saying something is X, describing a thing or saying how things are)
So because the topic (marked with は) is room, we're obviously talking about either a specific room, or rooms in general (no particular room). "Where is a room" is like a general rhetorical question - where is a room located? It doesn't really make a lot of sense. "Where is the room" just fits better - you want to know where a specific room is located
The other reading of "where is a room" (meaning "where does a room exist?") makes more sense (even if it's awkward English) - but the important point is that's a question about existence, which would need あります instead of です.
Sorry that was a bit long, but hopefully it helps people get a better intuitive sense of what Japanese sentences mean, and then translating it into the same idea in English gets a bit easier