When starting the React Native application with react-native run-android, react-native run-ios or react-native start --reset-cache. It will generate more logs in the terminal or command line. Some actions are generated after instrumentation of the code in the Metro transformer so it will be shown here. And will help in the investigation.
How to get the metro logs? As mentioned it will be found in the terminal or command line. See screenshot for reference.
NOTE: You can copy/paste the logs from start to finish into a .txt file for easier investigation.