Side
Side Of Something, Part
noun, suffix
The kanji and the word are exactly the same. That means they share meanings as well.
You've learned the がわ as the reading for this kanji, but when its used on its own as a vocabulary word, it is read as そば. Here's a mnemonic to help you remember:
Having a sober(そば) person by your side is important when you're drunk.
Think of other vocabulary words that use がわ. In these words, 側 is a suffix, so it will have another kanji that comes before it.
もう少しだけ、側にいてもいい？
Can I stay by your side a little longer?
お母さんの側をはなれちゃダメだよ！
Don't leave mom's side, okay?
ソファの側にサボテンがほしいなと思ってるの。
I'm thinking of putting a cactus next to the sofa.