NullReferenceException: Object reference not set to an instance of an object

Question

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

public class PlayerController : MonoBehaviour
{
private Rigidbody playerRB;
public GameObject focalPoint;
public float speed = 30;

// Start is called before the first frame update  
void Start()  
{  
    playerRB = GetComponent<Rigidbody>();  
    focalPoint = GameObject.Find("Focal Point");  
}  

// Update is called once per frame  
void Update()  
{  
    float forwardInput = Input.GetAxis("Vertical");  
    playerRB.AddForce(focalPoint.transform.forward * forwardInput * speed);  
}  

}