If you get any more Error during build can check IONIC Official FAQ ERROR
npm install -g cordova ionic
You also need to install Gradle before make native build.
Run your app in IOS emulator
$ ionic cordova platform add ios
$ ionic cordova run ios
Lately there some issue with ios-sim and if you found this error :
Error: Cannot read property 'replace' of undefined.
Please do the following:
//Go to this directorycd platforms/ios/cordova/node_modules///Run Below commandsudo npm install ios-sim@latest
Run your app in Android emulator
$ ionic cordova platform add android
$ ionic cordova run android
If you receive any error with 404 then First run this command: ionic cordova plugin add call-number
You can use genymotion instead of android default emulator because it will Fast to Load.
Still if their any error that not able to resolve then contact on github