Object Control in Unity

Here I share my code as to how to rotate the object around, zoom in and out, and translate in the game environment. I think you could use a similar approach for your camera (I initially wanted to move the camera around, that's why the name), but you would need some tweaking around. Hope this can help! 

P.S. : I might upload an update to explain my code, but now this should do :D

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class camera_movement : MonoBehaviour

{

     [SerializeField] float rotate_sensitivity = 160f;

     [SerializeField] float scale_sensitivity = 2f;

     [SerializeField] float trans_sensitivity = 5f;

     private void Update() {

        if(Input.GetKey(KeyCode.A))

        {

            transform.RotateAround(transform.position, Vector3.up, rotate_sensitivity * Time.deltaTime);

        }

        else if(Input.GetKey(KeyCode.D))

        {

            transform.RotateAround(transform.position, Vector3.down, rotate_sensitivity * Time.deltaTime);

        }

        else if(Input.GetKey(KeyCode.W))

        {

            transform.RotateAround(transform.position, Vector3.right, rotate_sensitivity * Time.deltaTime);

        }

        else if(Input.GetKey(KeyCode.S))

        {

            transform.RotateAround(transform.position, Vector3.left, rotate_sensitivity * Time.deltaTime);

        }

        else if(Input.GetKey(KeyCode.Q))

        {

            transform.localScale +=  transform.localScale * scale_sensitivity * Time.deltaTime;

        }

        else if(Input.GetKey(KeyCode.E))

        {

            transform.localScale -=  transform.localScale * scale_sensitivity * Time.deltaTime;

        }

        if(Input.GetKey(KeyCode.UpArrow))

        {

            transform.position +=  Vector3.up *trans_sensitivity * Time.deltaTime;

        }

        else if(Input.GetKey(KeyCode.DownArrow))

        {

            transform.position +=  Vector3.down * trans_sensitivity * Time.deltaTime;

        }

        else if(Input.GetKey(KeyCode.RightArrow))

        {

            transform.position +=  Vector3.right * trans_sensitivity * Time.deltaTime;;

        }

        else if(Input.GetKey(KeyCode.LeftArrow))

        {

            transform.position +=  Vector3.left * trans_sensitivity * Time.deltaTime;;

        }

     }

}