Rotate The Player in a given direction

I originally posted this on the Unity Forums but I'll go ahead and post it here as well.

Hello, i'm currently creating a top-down 3D shooter project and am at the testing phase where I'm testing the player's movement and so far it seems to be working well. I've gotten the camera to follow the player and have also implemented a way to allow the player to be able to shoot (even though it might still need a little bit of work). I also wanted to add a way to be able to have the player press the ABXY controls on a gamepad in order to rotate the player object/mesh and face a specific direction without it affecting the current directional movement (ex. using the directional pad or key input press for movement and using the abxy buttons to rotate/face the player object in said direction). However, this is where I'm currently having trouble as so far I don't exactly know how to make a player face a specific direction.

i've tryed using PlayerObj.transform.Rotate (Vector3.up RotationSpeed Time.deltaTime); but this only causes the PlayerObject to rotate around rather than a given direction.

I'll go ahead and share the code that I have so that anyone can get a better idea of what I currently have.

Edit: also apologies for my beginner-esque way of coding, I am just a beginner when it comes to Unity and am trying to further improve both in Unity and C# as a whole.

Player script:

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

 public class Player : MonoBehaviour
 {
     [Header("Player Camera")]
     [Tooltip("Select the camera to follow the player")]
     public GameObject camera;

     [Header("Player Movement Values")]
     [Tooltip("Main Player Object")]
     public GameObject PlayerObj;

     [Tooltip("Player Obj Movement Speed")]
     public float movementSpeed;

     [Tooltip("Player Mesh Rotation Speed")]
     public float RotationSpeed;

     private Rigidbody rb;
     private Vector3 direction;

     //public Vector3 Movement;

     [Header("Player Bullet Component")]
     [Tooltip("Bullet Spawn Point Object")]
     public GameObject bulletSpawnPoint;
     public GameObject Bullet;
     public float waitTime;
     private Transform BulletSpawned;

     void Start()
     {
         rb = GetComponent<Rigidbody> ();
     }

     void _Shoot()
     {
         BulletSpawned = Instantiate (Bullet.transform, bulletSpawnPoint.transform.position, Quaternion.identity);
         BulletSpawned.rotation = bulletSpawnPoint.transform.rotation;
     }

     void Movement()
     {
         float horizontalMove = Input.GetAxisRaw ("Horizontal");
         float verticalMove = Input.GetAxisRaw ("Vertical");

         direction = new Vector3 (x: horizontalMove, y: 0.0f, z: verticalMove);

         if (direction != Vector3.zero)
         {
             transform.rotation = Quaternion.Slerp (a: transform.rotation, b: Quaternion.LookRotation (direction), t: RotationSpeed * Time.deltaTime);
         }
         rb.MovePosition (transform.position + movementSpeed * Time.deltaTime * direction);
     }

     // Update is called once per frame
     void Update ()
     {
         Movement ();

         if (Input.GetKey (KeyCode.L) || (Input.GetKey (KeyCode.R)))
         {
             _Shoot ();
         }
         /*if (Input.GetKey (KeyCode.A))
         {
         PlayerObj.transform.Rotate (Vector3.up * RotationSpeed * Time.deltaTime);
         }*/
     }
 }

PlayerCamera script:

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

 public class PlayerCamera : MonoBehaviour
 {
     [Header("Variables")]
     public Transform player;
     public float smooth = 0.3f;
     public float height;

     private Vector3 velocity = Vector3.zero;
  
     // Update is called once per frame
     void Update ()
     {
         Vector3 pos = new Vector3 ();
         pos.x = player.position.x;
         pos.y = player.position.y + height;
         pos.z = player.position.z - 1f;
 
         transform.position = Vector3.SmoothDamp (transform.position, pos, ref velocity, smooth);
     }
 }

Bullet script:

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

 public class Bullet : MonoBehaviour
 {
     [Header("Variables")]
     public float Speed;
 
     public float maxDistance;
  
     // Update is called once per frame
     void Update ()
     {
         transform.Translate (Vector3.forward * Time.deltaTime * Speed);
         maxDistance += 1 * Time.deltaTime;
          
         if (maxDistance >= 2)
             Destroy (this.gameObject);
     }
 }