Android studio- can not start a new activity using intent

I am working on Android Studio app and I have just created a menu bar with three options. I am now trying to load a new activity when the menu items are selected. The problem I am having: When clicking on a menu item it opens a blank activity and not the fragment i have selected .

This is what I have done:

1. created java classes and XML pages for each corresponding menu item.

I will show the code for only my main activity and one of the new activity pages I created.

    friendListFragment.java

This is a new java class I created
    package com.example.assignment1;

import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.os.Bundle;
import android.view.ViewGroup;
import android.view.View;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;

public class friendListFragment extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
    }
}

and then in my main activity file i have the following

package com.example.assignment1;

import androidx.annotation.NonNull;
import androidx.appcompat.app.ActionBarDrawerToggle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import android.content.Intent;
import android.os.Bundle;
import android.view.MenuItem;
import android.os.Bundle;
import android.view.View;
import android.view.Menu;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import com.google.android.material.navigation.NavigationView;

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
    private DrawerLayout drawer;

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

        Toolbar toolbar = findViewById(R.id.toolBar);
        setSupportActionBar(toolbar);

        drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar,
                R.string.navigation_drawer_open,R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();
    }
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item ){
        Intent intent = null;
        switch (item.getItemId()){
            case R.id.viewFriendList:
                intent = new Intent(this,friendListFragment.class);
                startActivity(intent);
                break;
            case R.id.toDoList:
                intent = new Intent(this,toDoListFragment.class);
                startActivity(intent);
                break;
            case R.id.eventList:
                intent = new Intent(this,eventFragment.class);
                startActivity(intent);
                break;
            default:
                return super.onOptionsItemSelected(item);
        }
        drawer.closeDrawer(GravityCompat.START);

        return true;
    }


    @Override
    public void onBackPressed() {
        if (drawer.isDrawerOpen(GravityCompat.START)){
            drawer.closeDrawer(GravityCompat.START);
        }
        else
        {
            super.onBackPressed();
        }

    }

}

I have created this from an empty activity when I do not click on any menu options the menu bar appears correctly. Also, I think the error is in the onNavigationItemSelected function.

this is the error i am getting in my logcat

08-14 15:45:27.834 6816-6833/com.example.assignment1 E/Surface: getSlotFromBufferLocked: unknown buffer: 0xae613460

and this is my manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.assignment1">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
<activity android:name=".friendListFragment"></activity>
            <activity android:name=".toDoListFragment"></activity>
            <activity android:name=".eventFragment"></activity>
    </application>

</manifest>

Basically, when i click on an option in the menu bar it loads a blank page