Getting data from Firebase firestore to Android app

[Kormaican]

The app needs a class (data class?) or something to run as the getter for data from Firebase to the app. Kotlin seems to be built around this functionality, but I do not understand how to code it properly [yet].
Get started with Cloud Firestore
This link goes through the basics, but not setting up the getter class (if that's what is needed, still unsure.

Another potentially helpful links
https://firebase.google.com/docs/database/android/read-and-write
https://kotlinlang.org/docs/reference/data-classes.html
https://kotlinlang.org/docs/reference/idioms.html

[Kormaican]

https://proandroiddev.com/firebase-android-series-firestore-17e8951c574e
Helpful Kotlin Firestore tutorial

[Kormaican]

Use this for setup of reading data https://firebase.google.com/docs/firestore/query-data/get-data
Queryinghttps://firebase.google.com/docs/firestore/query-data/query-cursors