how to implement login signup page for android dev

public class LoginSignupActivity extends AppCompatActivity {

    private EditText usernameEditText, passwordEditText;
    private Button loginButton, signupButton;
    private SQLiteDatabase db;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login_signup);

        usernameEditText = findViewById(R.id.username);
        passwordEditText = findViewById(R.id.password);
        loginButton = findViewById(R.id.login_button);
        signupButton = findViewById(R.id.signup_button);

        // Initialize SQLite database
        db = openOrCreateDatabase("TravelBookingDB", MODE_PRIVATE, null);
        db.execSQL("CREATE TABLE IF NOT EXISTS users(username VARCHAR, password VARCHAR);");

        loginButton.setOnClickListener(v -> login());
        signupButton.setOnClickListener(v -> signup());
    }

    private void login() {
        String username = usernameEditText.getText().toString();
        String password = passwordEditText.getText().toString();
        Cursor cursor = db.rawQuery("SELECT * FROM users WHERE username=? AND password=?", new String[]{username, password});
        if (cursor.getCount() > 0) {
            // Login successful, navigate to next activity
            Intent intent = new Intent(LoginSignupActivity.this, MainActivity.class);
            startActivity(intent);
        } else {
            // Login failed, show error message
            Toast.makeText(this, "Invalid username or password", Toast.LENGTH_SHORT).show();
        }
        cursor.close();
    }

    private void signup() {
        String username = usernameEditText.getText().toString();
        String password = passwordEditText.getText().toString();
        db.execSQL("INSERT INTO users(username, password) VALUES(?, ?);", new Object[]{username, password});
        Toast.makeText(this, "Signup successful", Toast.LENGTH_SHORT).show();
    }
}