Noun and の adjective
うちがわ
りそな銀行の内側で待っています。
I'll wait for you inside Resona Bank.
右の内側のかかとにトゲがささったみたいです。
I think I've got a splinter in my inner right heel.
ゾンビを中に入れないために、金属製のシャッターを下ろして、内側から鍵を掛ける必要があります。
We need to lower the metal shutters and lock them from the inside to shut the zombies out.
The inside side is the inside. A little redundant but makes a lot of sense.
The readings are the kun'yomi readings. With 側 you've already learned it. With 内 you've also already learned the reading. Combine them together and you have うちがわ. In case you've forgotten, here's a mnemonic to help you remember that pesky うち portion. What is it that's drawn you inside? "Oo, cheese!" (うち) Cheese has drawn you inside. You're so excited that you exclaim, "Oo, cheese!"