Navigation drawer doesn't bring me to second screen – Flutter

I am making a bus app to learn more about flutter and dart language. So, i came across this problem with the navigation drawer where it doesn’t go to the screen it’s supposed to go to when I clicked on it. It just stays the same.

This is my code for the main screen.

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);
  @override
  State<StatefulWidget> createState() {
    return MainScreen();
  }
}

class MainScreen extends State<MyApp> {
  final currentTime = DateTime.now();
  final busStopController = TextEditingController();

  //To customise the greeting according to the time
  String greeting() {
    var hour = DateTime.now().hour;
    if (hour < 12) {
      return 'Morning';
    }
    if (hour < 17) {
      return 'Afternoon';
    }
    return 'Evening';
  }

  //Strings for user input and busStop
  String name = '';
  String busStop = '';

  //Strings for different bus timings
  String sb1timing = '';
  String sb2timing = '';
  String sb3timing = '';
  String sb4timing = '';

  //Different icon colors for bus capacity
  final Color _iconColorEmpty = Colors.green;
  final Color _iconColorHalf = Colors.orange;
  final Color _iconColorFull = Colors.red;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        backgroundColor: Colors.transparent,
        drawer: Drawer(
          child: ListView(
            padding: EdgeInsets.zero,
            children: [
              const DrawerHeader(
                decoration: BoxDecoration(
                  color: Colors.black45,
                ),
                child: Text(
                  'WaitLah! bus services',
                  style: TextStyle(
                      fontWeight: FontWeight.bold,
                      color: Colors.white,
                      fontSize: 20),
                ),
              ),
              ListTile(
                leading: const Icon(
                  Icons.directions_walk_outlined,
                  color: Colors.black,
                ),
                title: const Text(
                  'Plan Your Journey',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
                ),
                onTap: () {
                  Navigator.push(
                      context,
                      MaterialPageRoute(
                          builder: (context) => PlanJourneyScreen()));
                },
              ),

And this is my code for the second screen (PlanJourneyScreen)

    class PlanJourneyScreen extends StatelessWidget {
  const PlanJourneyScreen({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        const Backgroundimage(),
        Scaffold(
          backgroundColor: Colors.transparent,
          appBar: AppBar(
            elevation: 0.0,
            backgroundColor: Colors.transparent,
            centerTitle: true,
            title: Text(
              'Plan Your Journey s10194266d',
              style: GoogleFonts.kalam(
                  textStyle: const TextStyle(
                      fontSize: 24, fontWeight: FontWeight.bold)),
            ),
          ),
          body: Column(
            mainAxisAlignment: MainAxisAlignment.start,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              const SizedBox(
                height: 30,
              ),
              Text(
                'Please state your source and destination.',
                textAlign: TextAlign.center,
                style: GoogleFonts.montserrat(
                    textStyle: const TextStyle(
                        fontSize: 17,
                        color: Colors.white,
                        fontWeight: FontWeight.bold)),
              ),
              Padding(
                padding: const EdgeInsets.fromLTRB(20, 30, 10, 10),
                child: Text(
                  'Source',
                  textAlign: TextAlign.left,
                  style: GoogleFonts.montserrat(
                    textStyle: const TextStyle(
                        fontSize: 15,
                        fontWeight: FontWeight.bold,
                        color: Colors.white),
                  ),
                ),
              ),
              TextField(
                decoration: InputDecoration(
                  enabledBorder: OutlineInputBorder(
                      borderSide: const BorderSide(color: Colors.white),
                      borderRadius: BorderRadius.circular(10.0)),
                ),
              ),
              Padding(
                padding: const EdgeInsets.fromLTRB(20, 30, 10, 10),
                child: Text(
                  'Destination',
                  style: GoogleFonts.montserrat(
                    textStyle: const TextStyle(
                        fontSize: 15,
                        fontWeight: FontWeight.bold,
                        color: Colors.white),
                  ),
                ),
              ),
              TextField(
                style: const TextStyle(color: Colors.white),
                decoration: InputDecoration(
                  enabledBorder: OutlineInputBorder(
                      borderSide: const BorderSide(color: Colors.white),
                      borderRadius: BorderRadius.circular(10.0)),
                ),
                onTap: () {},
              ),
              Container(
                padding: const EdgeInsets.fromLTRB(0, 30, 0, 0),
                child: ElevatedButton(
                  style: ElevatedButton.styleFrom(
                      primary: Colors.white54,
                      shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(32.0)),
                      minimumSize: Size(90, 40)),
                  onPressed: () {},
                  child: Text(
                    'Calculate!',
                    style: GoogleFonts.montserrat(
                      textStyle: const TextStyle(
                          fontSize: 16, fontWeight: FontWeight.bold),
                    ),
                  ),
                ),
              ),
              Container()
            ],
          ),
        ),
      ],
    );
  }
}