West Side
West
noun, の adjective
The West side of something is known as the West or the West side. Sorry, I have no story to go along with your West side.
The readings are the kun'yomi vocab readings. You should know both of them, with 西 being にし and 側 being がわ (what you learned with the kanji).
この町の西側のゆう便局で働いています。
I'm working at the post office on the west side of this town.
西側しょ国とみなされるのはどの国ですか。
Which countries are considered Western countries?
今年の二月三日に巻き寿司を食べるなら、西側を向いて食べなくてはいけませんよ。
If you eat makizushi on Feb 3rd of this year, you have to face west.