To complete your app development and deploy it to Google Play and App Store, you need more additional changes. Please follow guides bellow for more details.

Change App Icons

Add App Icons and Launch Screens to React Native Apps (iOS & Android) guide by Scott Stewart on medium.com

Running on Device

Running On Device guide from React Native

Publishing to Google Play Store

https://reactnative.dev/docs/signed-apk-android

13 steps to Deploying React-Native Android App to Google Play Store using Android Studio guide by Jolanta on medium.com

Publishing to App Store

How to Deploy a React Native IOS app on the App Store guide on readybytes.in