Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word:
You see a man walking east, toward the sun rising behind that tree, but it's too bright. He trips and he gashes (ひがし) his foot on a root that was sticking out of the ground. His foot is torn up really bad, but he tries to take another step and, oh no, he gashes his foot again! This guy is not having an easy time going east.
Let’s meet in the cafe that's on the east side of the station.
Which direction is east?
I live on the east side of the airport.