i want to add touch controlls to my game. how can i do so? *free candy for whoever helps me out*

so i want to add touch controlls to my game, and i have no idea how to do so. could someone help me out with this? the script im using for my controls is: using UnityEngine; using UnityEngine.UI; using System.Collections; using UnityEngine.SceneManagement;

 public class PlayerController : MonoBehaviour
 {
 
     public float speed;
     public Text countText;
     public Text winText;
 
     private Rigidbody rb;
     private int count;
 
     void Start()
     {
         rb = GetComponent<Rigidbody>();
         count = 0;
         SetCountText();
         winText.text = "";
     }
 
     void FixedUpdate()
     {
         float moveHorizontal = Input.GetAxis("Horizontal");
         float moveVertical = Input.GetAxis("Vertical");
 
         Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);
 
         rb.AddForce(movement * speed);
     }
 
     void OnTriggerEnter(Collider other)
     {
         if (other.gameObject.CompareTag("Pick Up"))
         {
             other.gameObject.SetActive(false);
             count = count + 1;
             SetCountText();
         }
     }
 
     void SetCountText()
     {
         countText.text = "Count: " + count.ToString();
         if (count >= 12)
         {
             winText.text = "You Win!";
 
           
         }
     } 
 }
 

will i have to create a new version of the script that can work on touch devices like android and ios or can i just edit this script? im really new to scripting and unity so yeah lol