Make UI button or Joystick Problem

Hi, @vbvbnbbbj , now i am study course https://www.html.it/pag/364391/unity-platform-2d-creare-personaggio/ But when i copy create 2 script and copy code, i have 31 errors. My version: First class = class Move:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Move: PhysicsObject
 {
     public float maxSpeed = 7;
     public float jumpTakeOffSpeed = 7;
     private SpriteRenderer spriteRenderer;
     private Animator animator;
     // Use this for initialization
     void Awake()
     {
         spriteRenderer = GetComponent<SpriteRenderer>();
         animator = GetComponent<Animator>();
     }
     
     protected override void ComputeVelocity()
     {
         Vector2 move = Vector2.zero;
         move.x = Input.GetAxis("Horizontal");
         if (Input.GetButtonDown("Jump") && grounded) 
         {
             velocity.y = jumpTakeOffSpeed;
         }
         else if (Input.GetButtonUp("Jump"))
         {
             if (velocity.y > 0)
             {
                 velocity.y = velocity.y * 0.5f;
             } 
         }
         bool flipSprite = (spriteRenderer.flipX ? (move.x > 0.01f) : (move.x > 0.01f));
         if (flipSprite)
         {
             spriteRenderer.flipX = !spriteRenderer.flipX;
         }
         animator.SetBool("grounded", grounded);
         animator.SetFloat("velocityX", Mathf.Abs(velocity.x) / maxSpeed);
         targetVelocity = move * maxSpeed;
     }
 }

Second class = PhysicsObject:

 //Script PhysicsObject
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 public class PhysicsObject : MonoBehaviour
 {
     public float minGroundNormalY = .65f;
     public float gravityModifier = 1f;
     protected Vector2 targetVelocity;
     protected bool grounded;
     protected Vector2 groundNormal;
     protected Rigidbody2D rb2d;
     protected Vector2 velocity;
     protected ContactFilter2D contactFilter;
     protected RaycastHit2D[] hitBuffer = new RaycastHit2D[16];
   //  protected List hitBufferList = new List(16);
    protected List<RaycastHit2D> hitBufferList = new List<RaycastHit2D> (16);
 
     protected const float minMoveDistance = 0.001f;
     protected const float shellRadius = 0.01f;
     void OnEnable()
     {
         rb2d = GetComponent<Rigidbody2D>();
     }
     void Start()
     {
         contactFilter.useTriggers = false;
         contactFilter.SetLayerMask(Physics2D.GetLayerCollisionMask(gameObject.layer));
         contactFilter.useLayerMask = true;
     }
     void Update()
     {
         targetVelocity = Vector2.zero;
         ComputeVelocity();
     }
     protected virtual void ComputeVelocity()
     {
     }
     void FixedUpdate()
     {
         velocity += gravityModifier * Physics2D.gravity * Time.deltaTime;
         velocity.x = targetVelocity.x;
         grounded = false;
         Vector2 deltaPosition = velocity * Time.deltaTime;
         Vector2 moveAlongGround = new Vector2(groundNormal.y, -groundNormal.x);
         Vector2 move = moveAlongGround * deltaPosition.x;
         Movement(move, false);
         move = Vector2.up * deltaPosition.y;
         Movement(move, true);
     }
     void Movement(Vector2 move, bool yMovement)
     {
         float distance = move.magnitude;
         if (distance > minMoveDistance)
         {
             hitBufferList.Clear();
             int count = rb2d.Cast(move, contactFilter, hitBuffer, distance + shellRadius);
             for (int i = 0; i < count; i++) {
                 hitBufferList.Add(hitBuffer[i]);
             }
 
             for (int i = 0; i < hitBufferList.Count; i++)
             {
                 Vector2 currentNormal = hitBufferList[i].normal;
                 if (currentNormal.y > minGroundNormalY)
                 {
                     grounded = true;
                     if (yMovement)
                     {
                         groundNormal = currentNormal;
                         currentNormal.x = 0;
                     }
                 }
                 
                 float projection = Vector2.Dot(velocity, currentNormal);
                 if (projection < 0)
                 {
                     velocity = velocity - projection * currentNormal;
                 }
                 float modifiedDistance = hitBufferList[i].distance - shellRadius;
                 distance = modifiedDistance < distance ? modifiedDistance : distance;
             }
         }
         rb2d.position = rb2d.position + move.normalized * distance;
     }
 }