I wanted to sleep so that I could be ready for my night shift, but I couldn’t because the trains were too noisy.
You move towards the sake. When you move towards it, you are doing something for the sake of. But why use fancy language like that? Let's just leave it as for.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: For the sake of public safety, you will need to tame (ため) the wild beasts loose in our city. Now go, tame them!