react native the iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.5.99.
Just Manually Update Development target in xcode Pods file.
The problem is in your pod files deployment target iOS Version not in your project deployment target iOS Version, so you need to change the deployment iOS version for your pods as well to anything higher than 8.0 to do so open your project workspace and do this:
Click on pods.
Select each project and target and click on build settings.
Under Deployment section change the iOS Deployment Target version to anything more than 8.0 (better to try the same project version).
Repeat this for every other project in your pods then run the app.