CameraController.cs

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

public class CameraController : MonoBehaviour {

    public float offsetX;
    public float offsetY;
    public Transform targetTrans;

void Start () {
        if (targetTrans == null)
        {
            targetTrans = GameObject.FindGameObjectWithTag("Player").GetComponent<Transform>();
		if(targetTrans == null)
            {
                return;
            }
        }
    }
	
    void LateUpdate()
    {
        this.transform.position = new Vector3
		(playerTrans.position.x + offsetX, 
		 playerTrans.position.y + offsetY, 
		 -10);
    }
}