add menu_menu.xml to menu folder in res folder

add following code
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:title="Settings" android:id="@+id/settings"></item>
    <item android:title="Help" android:id="@+id/help"></item>
</menu>

code for activity file

package com.example.zappycode.menudemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        MenuInflater menuInflater = getMenuInflater();
        menuInflater.inflate(R.menu.main_menu,menu);

        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        super.onOptionsItemSelected(item);

        switch (item.getItemId()) {
            case R.id.settings:
                Log.i("Item Selected","Settings");
                return true;
            case R.id.help:
                Log.i("Item Selected","Help");
                return true;
            default:
                return false;
        }
    }

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