Capacitor’s philosophy is to embrace the native project tooling and IDE’s instead of providing an abstracted config file like Cordova. As a general strategy, you’d search for “how to do X in Xcode?” or “… in Android Studio?”
For this question, setting Android version code, see here - most settings are configured in AndroidManifest.xml or the build.gradle.
For CGBundleVersion, it’s in Info.plist.