Interactive rating component with JS

I tried my best to use what I've learned so far. (I'm Korean. my English is not good enough so I'd appreciate it if you let me know when you don't understand my sentence.)

I wasn't sure of my codes. especially,

if (num.length>1 && ratingNum!=num[num.length-2] ){ storage[storage.length-2].classList.remove('colorChange') }

<- this part. I think there would be a better solution using only 'num.length' without using variable "storage" .

I'm a newbie so I'm not sure it is okay with my html, css and js...

feel free to point out my work.

Thank you.