Quick question with a Camera Following script

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

public class CameraFollow : MonoBehaviour {

    public Transform CameraTr;
    public Transform PlayerTr;
    Vector3 CameraStartingPos = CameraTr.position;

	void Start () {
	// Update is called once per frame
	void Update () {
        CameraTr.position = PlayerTr.position + CameraStartingPos;

So the error comes in the “Vector 3 line” and I’m guessing Unity doesnt think of the position argument as a Vector and that’s why I can’t set CameraStartingPos as CameraTr.position.
Could anyone explain me if I’m doing anything wrong or It’s just not done this way? Thanks :D.

Anyone please?
It just would make it easier for testing the best camera position.