Use an Intent

Add onclick method on main java file and xml file.

res > layout > activity_main.xml

<?xml version="1.0" encoding="utf-8" ?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:tools="http://chemas.android.com/tools"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="@color/tan_background"
	android:orientation="vertical"
	tools:context="com.example.android.miwok.MainActivity">

	<TextView
		android:id="@+id/numbers"
		style="@style/CategoryStyle"
		android:background="@color/category_numbers"
		android:text="Numbers"
		android:onClick="openNumberList" />

	<TextView
		android:id="@+id/family"
		style="@style/CategoryStyle"
		android:background="@color/category_family"
		android:text="Family Members" />

	<TextView
		android:id="@+id/colors"
		style="@style/CategoryStyle"
		android:background="@color/category_colors"
		android:text="Calors" />

	<TextView
		android:id="@+id/phrases"
		style="@style/CategoryStyle"
		android:background="@color/category_phrases"
		android:text="Phrases" />

</LinearLayout>

MainActivity.java

package com.example.android.miwok;

import android.conent.Intent;
import android.support.v7.app.AppCompactActivity;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompactActivity {

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

	public void openNumbersList(View view){
		//TODO: Write your code here!
		Intent i = new Intent(this, NumbersActivity.class);
		startActivity(i);
	}
}

android intent tutorial site
http://www.vogella.com/tutorials/AndroidIntent/article.html#usingintents_call