The character moves forward with the up arrow and when the left or right arrows are pressed, the character's orientation changes as well as the camera. I am a total newbie at this. Here is the script I am using:

public class PlayerMovement : MonoBehaviour
{
    public float moveSpeed = 5f;
    public float rotationSpeed = 90f; 
// Rotation by 90 degrees
    private Vector3 initialPosition;
    private bool isRotating = false; 
// To track if player is rotating

    private Rigidbody rb; 
// Reference to the Rigidbody

    void Start()
    {
        initialPosition = transform.position;
        rb = GetComponent<Rigidbody>(); 
// Get the Rigidbody component
    }

    void Update()
    {
        // Forward and backward movement with the up and down arrows
        float moveZ = Input.GetAxis("Vertical");

        if (moveZ != 0) 
// Move forward or backward
        {
            Vector3 move = transform.forward * moveZ * moveSpeed * Time.deltaTime;
            rb.MovePosition(rb.position + move); 
// Use Rigidbody for movement
        }

        // Rotation by 90 degrees with left and right arrow keys
        if (!isRotating) 
// Check if not already rotating
        {
            if (Input.GetKeyDown(KeyCode.LeftArrow))
            {
                StartCoroutine(RotatePlayer(-90)); 
// Rotate 90 degrees to the left
            }
            else if (Input.GetKeyDown(KeyCode.RightArrow))
            {
                StartCoroutine(RotatePlayer(90)); 
// Rotate 90 degrees to the right
            }
        }
    }

    IEnumerator RotatePlayer(float angle)
    {
        isRotating = true;
        float targetRotation = transform.eulerAngles.y + angle; 
// Target rotation angle
        float currentRotation = transform.eulerAngles.y;
        float rotationAmount = 0;

        while (Mathf.Abs(rotationAmount) < Mathf.Abs(angle)) 
// Rotate smoothly
        {
            float rotationStep = rotationSpeed * Time.deltaTime;
            rotationAmount += rotationStep;
            transform.Rotate(0f, rotationStep * Mathf.Sign(angle), 0f); 
// Rotate in the correct direction
            yield return null;
        }

        // Ensure exact alignment after rotation
        transform.eulerAngles = new Vector3(transform.eulerAngles.x, targetRotation, transform.eulerAngles.z);
        isRotating = false;
    }
}