how to make a first person controller in c#

     public float speed = 10.0f;
     public float straffeSpeed = 7.0f;
     public float jumpHeight = 3.0f;
     Rigidbody rb;
     
     
 
     // Start is called before the first frame update
     void Start()
     {
         Cursor.lockState = CursorLockMode.Locked;
         rb = GetComponent<Rigidbody>();
     }
 
     // Update is called once per frame
     void Update()
     {
         float DisstanceToTheGround = GetComponent<Collider>().bounds.extents.y;
         bool IsGrounded = Physics.Raycast(transform.position, Vector3.down, DisstanceToTheGround + 0.1f);
 
         float translation = Input.GetAxis("Vertical") * speed;
         float straffe = Input.GetAxis("Horizontal") * straffeSpeed;
         translation *= Time.deltaTime;
         straffe *= Time.deltaTime;
 
 
         //anim.SetTrigger("isWalking");
 
         transform.Translate(straffe, 0, translation);
         //rb.velocity = transform.forward * translation + transform.right * straffe ;
         
 
         if(IsGrounded && Input.GetKeyDown("space"))
         {
             Debug.Log("JUMP!");
             rb.velocity = new Vector3(0, jumpHeight, 0);            
         }
         
         if (Input.GetKey(KeyCode.R))
         {
             Scene scene = SceneManager.GetActiveScene(); 
             SceneManager.LoadScene(scene.name);
         }
 
         if (Input.GetKeyDown("escape"))
         {
             Application.Quit();
             //Cursor.lockState = CursorLockMode.None;
         }
 
     }
 }