how to make a basic movement for the player in unity code example

Example 1: how to add movement in unity

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

public class PlayerMovement : MonoBehaviour
{
    private string moveInputAxis = "Vertical";
    

    public float moveSpeed = 0.1f;
    public Rigidbody rb;
    public bool cubeIsOnTheGround = true;


    // Start is called before the first frame update
    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }
    
    // Update is called once per frame
    void Update()
    {
       float moveAxis = Input.GetAxis(moveInputAxis); 

       ApplyInput(moveAxis);

       if(Input.GetButtonDown("Jump") && cubeIsOnTheGround == true)
       {
           rb.AddForce(new Vector3(0, 7, 0), ForceMode.Impulse);
           cubeIsOnTheGround = false;
       } 

    private void ApplyInput(float moveInput)
    {
        Move(moveInput);
    }

    private void Move(float input)
    {
        transform.Translate(Vector3.forward * input * moveSpeed);
    }    

    private void OnCollisionEnter(Collision collision) {
        if(collision.gameObject.tag == "Ground") {
            cubeIsOnTheGround = true;
        }
    }
}

Example 2: simple first person camera unioty

//Fixed the issues with the previous controller
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CameraLook : MonoBehaviour
{
	public float minX = -60f;
	public float maxX = 60f;

	public float sensitivity;
	public Camera cam;

	float rotY = 0f;
	float rotX = 0f;

	void Start()
	{
		Cursor.lockState = CursorLockMode.Locked;
		Cursor.visible = false;
	}

    void Update()
    {
		rotY += Input.GetAxis("Mouse X") * sensitivity;
		rotX += Input.GetAxis("Mouse Y") * sensitivity;

		rotX = Mathf.Clamp(rotX, minX, maxX);

		transform.localEulerAngles = new Vector3(0, rotY, 0);
		cam.transform.localEulerAngles = new Vector3(-rotX, 0 0);

		if (Input.GetKeyDown(KeyCode.Escape))
		{
        	//Mistake happened here vvvv
			Cursor.lockState = CursorLockMode.None;
			Cursor.visible = true;
		}

		if (Cursor.visible && Input.GetMouseButtonDown(1))
		{
			Cursor.lockState = CursorLockMode.Locked;
			Cursor.visible = false;
		}
	}
}