Unity Android Touch Controls UP DOWN LEFT RIGHT

I made a game for windows but now i want to made it for android for that, i need a c# script to control my player that is inside a Gameobject. I need the controls for up down left and right to test on my android device. My windows version control script is below: Can someone explain how to create a script to add touch controls (up down left right)

using System.Collections;

public class controlodejogador : MonoBehaviour {

 public GameObject player;

 public float AlturaMaxima;
 public float AlturaMinima;

 public float speedY;
 public float speedX;
 public int pontuaçao;
 public int score;
 public TextMesh pontos;
  


 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () {
 
     float translationY = Input.GetAxis ("Vertical") * speedY;
     float translationX = Input.GetAxis ("Horizontal") * speedX;
     player.transform.Translate (translationX, translationY, 0);

     if (player.transform.position.y > AlturaMaxima) {
         player.transform.position = new Vector2 (player.transform.position.x,AlturaMaxima);
             }
         if (player.transform.position.y < AlturaMinima) {
         player.transform.position = new Vector2(player.transform.position.x,AlturaMinima);
         }