Slingshot Education, Advice on how to launch a mobile app

I’m looking for an experienced mobile app consultant to guide me through the final stages of launching a React Native mobile app built with Expo.

The app’s UI and core user flows are complete and have been tested successfully using Expo Go. At this stage, I’m not looking for someone to rebuild the app, but rather a professional who can consult and advise me on best practices to take the project from a finished design to a live app on the Apple App Store and Google Play Store.

Current Status:
React Native (Expo) app
UI/UX complete and functioning
Bottom tab navigation implemented
Mock data currently in use
Tested locally via Expo Go
No backend or authentication connected yet

What I Need Help With
I’m looking for guidance and light hands-on support covering:

Firebase setup (Authentication, Firestore/Realtime DB, structure best practices)
Advice on user authentication flows (email login, future scalability)
How to securely connect Firebase to an Expo app
Preparing the app for production builds
App Store & Play Store submission process (certificates, builds, store listings)
Understanding ongoing app maintenance after launch
General best practices to avoid common launch mistakes

What I’m Looking For

Someone with real-world experience launching React Native / Expo apps
Strong knowledge of Firebase
Familiarity with App Store & Google Play submission
Comfortable working as a consultant/mentor, not just a developer-for-hire
Able to explain things clearly so I can manage the app myself long-term