I just started working on 3d game development in unity and tried to copy a script tutorial I found on YouTube for basic enemy detection (https://www.youtube.com/watch?v=9ts9qXt8o2k). The tutorial goes back into Unity at minute 8 without any problems but I keep getting the error stated in the title.

Here is the exact script I have at the moment (Unity states the error at 47,36 aka the if(Physics.Raycast line):

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Enemy : MonoBehaviour
{
    public float Maxspeed;
    private float Speed;

    private Collider[] hitColliders;
    private RaycastHit Hit;

    public float SightRange;
    public float DetectionRange;

    public Rigidbody rb;
    public GameObject Target;

    private bool seePlayer;


    // Start is called before the first frame update
    void Start()
    {
        Speed = Maxspeed;
    }

    // Update is called once per frame
    void Update()
    {
        // detect if a player is in range

        if (!seePlayer)
        {
            hitColliders = Physics.OverlapSphere(transform.position, DetectionRange);
            foreach (var HitCollider in hitColliders)
            {
                if(HitCollider.tag == "Player")
                {
                    Target = HitCollider.gameObject;
                    seePlayer = true;
                }
            }
        }
        else
        {
            if(Physics.RayCast(transform.position, (Target.transform.position - transform.position), out Hit, SightRange))
            {
                if(Hit.collider.tag != "Player")
                {
                    seePlayer = false;
                }
                else
                {
                    //calculate the player's direction

                    var Heading = Target.transform.position - transform.position;
                    var Distance = Heading.magnitude;
                    var Direction = Heading / Distance;


                    Vector3 Move = new Vector3(Direction.x * Speed, 0, Direction.z * Speed);
                    rb.velocity = Move;
                    transform.forward = Move;
                }
            }
        }
    }
}

The title is the entire name for the error I received minus the time of the error and the file name. I have tried changing line 47 to start with if(UnityEngine.Physics.RayCast but still got the error.