PlayerMovement

CameraController.cs

using UnityEngine;

public class CameraController : MonoBehaviour
{
    public float sensivity = 1f;
    
    public Transform orientation;

    float xRotation = 0f;
    float yRotation = 0f;
    // Start is called once before the first execution of Update after the MonoBehaviour is created
    void Start()
    {
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;
    }

    // Update is called once per frame
    void Update()
    {
        float mouseX = Input.GetAxis("Mouse X") * Time.deltaTime * sensivity;
        float mouseY = Input.GetAxis("Mouse Y") * Time.deltaTime * sensivity;

        xRotation -= mouseY;
        xRotation = Mathf.Clamp(xRotation, -90f, 90f);
        yRotation += mouseX;

        transform.rotation = Quaternion.Euler(xRotation, yRotation, 0f);
        orientation.rotation = Quaternion.Euler(0f, yRotation, 0f);
    }
}

MoveCamera.cs

using UnityEngine;

public class MoveCamera : MonoBehaviour
{
    public Transform cameraPosition;
    // Update is called once per frame
    void Update()
    {
        transform.position = cameraPosition.position;
    }
}

PlayerMovement.cs

using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    [Header("Movement")]
    public float moveSpeed = 5f;
    public float groundDrag;
    public float jumpForce;
    public float jumpCooldown;
    public float airMultiplier;
    bool readyToJump = true;
    
    [Header("Ground Check")]
    public float playerHeight = 1.8f;
    public LayerMask groundLayer;
    bool  grounded;

    [Header("Keybinds")]
    public KeyCode jumpKey = KeyCode.Space;

    public Transform orientation;

    float horizontalInput;
    float verticalInput;

    Vector3 moveDirection;

    Rigidbody rb => GetComponent<Rigidbody>();

    // Start is called once before the first execution of Update after the MonoBehaviour is created
    void Start()
    {
        rb.freezeRotation = true;
    }

    // Update is called once per frame
    void Update()
    {
        grounded = Physics.Raycast(transform.position, Vector3.down, playerHeight * .5f + 0.2f, groundLayer);

        MyInput();
        SpeedControl();
        rb.linearDamping = grounded ? groundDrag : 0;
    }

    void FixedUpdate()
    {
        MovePlayer();
    }
    
    void MyInput()
    {
        horizontalInput = Input.GetAxis("Horizontal"); // -1..0..1
        verticalInput = Input.GetAxis("Vertical");

        if (Input.GetKey(jumpKey) && readyToJump && grounded)
        {
            Jump();
            readyToJump = false;
            Invoke(nameof(ResetJump), jumpCooldown);
        }
    }

    void MovePlayer()
    {
        moveDirection = orientation.forward * verticalInput + orientation.right * horizontalInput;
        
        if (grounded)
            rb.AddForce(moveDirection * moveSpeed * 10f, ForceMode.Force);
        else
            rb.AddForce(moveDirection * moveSpeed * 10f * airMultiplier, ForceMode.Force);

    }

    void SpeedControl()
    {
        Vector3 flatVelocity = new (rb.linearVelocity.x, 0, rb.linearVelocity.z);

        if (flatVelocity.magnitude > moveSpeed)
        {
            flatVelocity = flatVelocity.normalized * moveSpeed;
            rb.linearVelocity = new Vector3(flatVelocity.x, rb.linearVelocity.y, flatVelocity.z);
        }
    }

    void Jump()
    {
        rb.linearVelocity = new Vector3(rb.linearVelocity.x, 0, rb.linearVelocity.z);
        rb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);
    }

    void ResetJump()
    {
        readyToJump = true;
    }
}