Duvida android Studio

Gente estou com esse código :

public class Inicial extends AppCompatActivity {


    private ImageButton button,button2;


            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_inicial);

                button = (ImageButton)findViewById(R.id.imageButton8);

                button.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {

                        Intent it = new Intent(Inicial.this,MainActivity.class);
                        startActivity(it);
                    }
                });

Quando clicar no botão ele abre essa Class:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
        tabLayout.addTab(tabLayout.newTab().setText("Praça XV - Araribóia"));
        tabLayout.addTab(tabLayout.newTab().setText("Araribóia - Praça XV"));
        tabLayout.addTab(tabLayout.newTab().setText("Tempo de viagem"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
        final PagerAdapter adapter = new PagerAdapter
                (getSupportFragmentManager(), tabLayout.getTabCount());
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
    }}

E tem esse PAGE ADAPTER

class PagerAdapter extends FragmentStatePagerAdapter {
    int mNumOfTabs;

    public PagerAdapter(FragmentManager fm, int NumOfTabs) {
        super(fm);
        this.mNumOfTabs = NumOfTabs;
    }

    @Override
    public Fragment getItem(int position) {

        switch (position) {
            case 0:
                TabFragment1 tab1 = new TabFragment1();
                return tab1;
            case 1:
                TabFragment2 tab2 = new TabFragment2();
                return tab2;
            case 2:
                TabFragment3 tab3 = new TabFragment3();
                return tab3;
            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return mNumOfTabs;
    }
}

Com todos os layouts e etc.

Agora eu quero colocar outro button pra abrir uma outra Activity com as mesmas 3 abas, mas com conteúdos diferentes.

Eu copiei e colei mas da CRASH no App.

Como eu posso fazer?