Wow I was able to understand your joke about splitting the room in half (at least I think I did) and I'm just at the first week.
Can 'podłoga' also refer to a floor of a building? Or does it only mean literally the floor?
Only literally the floor – storey/floor/level is „piętro”, excluding ground floor, which is „parter” and floors below ground are „poziomy”(singular: „poziom”).
Side note: „parter” affects numbering of floors in Polish – „pierwsze piętro” is second floor(assuming that ground floor is floor 1 for you, if you use the British numbering, it's the same).