Since this word is made up of a single kanji, it probably uses the kun'yomi reading. You did not learn this reading, so here's a mnemonic to help you:
You look at the floor. It's disgusting. Dirtiest and nastiest floor you've ever seen. You say yucka (ゆか) because it's covered in yucca (ゆか). Plus, it's all rotten.
I'll have to clean floor today.
A cockroach was crawling on the floor.
When I watch TV, I usually lay on the floor with my legs crossed.