HELP WITH SETTING

HI, I NEED HELP! I DON'T KNOW HOW TO SET THIS MOVEMENT! I GOT THIS CODE : using UnityEngine; using System.Collections; using UnityEngine.UI; using UnityEngine.EventSystems;

public class leftmovement1 : MonoBehaviour, IEventSystemHandler {

 public GameObject character;
 public float maxSpeed = 10f;
 bool buttonHeld = false;
 
 public void pressed (BaseEventData eventData)
 {
     buttonHeld = true;
 }
 public void notpressed(BaseEventData eventData)
 {
     buttonHeld = false;
 }
 void Start () 
 {
     character = GameObject.FindWithTag ("Kowboys");
 }
 public void Update()
 {
     if (buttonHeld)
     {
         // Do stuff
         Debug.Log ("click");
         // Move Character
         character.GetComponent<Rigidbody2D>().velocity = Vector3.right * maxSpeed;

     } 
     else
         Debug.Log ("not click");
 }

} HOW TO SET THE PLAYER AND BUTTON TO MOVE??