Hello, How are you?
I have read your requirement carefully.
I am a senior Native and Hybrid mobile app developer.
Please have a look on my portfolio.
https://www.freelancer.com/u/peng72083
I have rich experience about Java(Android Studio) and react-native.
Especially, I have experience to build wedding service app by using react native as you want, for my Taiwan client.
Please check my works.
https://www.freelancer.com/projects/mobile-phone/React-Native-App-iOS-Android-16993036/
https://www.freelancer.com/projects/mobile-phone/React-Native-App-iOS-Android-17166818/
https://www.freelancer.com/projects/mobile-phone/React-Native-App-iOS-Android-17264389/
To convert android java code to react native, and generate to iOS app, it is very interested for me.
Let's discuss more detail via private chat.
Hope to kindly reply,
Peng