implement movement in unity 3d 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: 3d movement unity

using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class playerMovement : MonoBehaviour {     
 public float speed = 25.0F;     
 public float jumpSpeed = 8.0F;      
 public float gravity = 20.0F;     
 private Vector3 moveDirection = Vector3.zero;
 private float turner;     
 private float looker;     
 public float sensitivity = 5;         
 // Use this for initialization     
 void Start () {              
 
 }          
 // Update is called once per frame     
 void Update () {         
      CharacterController controller = GetComponent<CharacterController>();
      // is the controller on the ground?         
      if (controller.isGrounded) {             
      //Feed moveDirection with input.             
      moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
      moveDirection = transform.TransformDirection(moveDirection);
      //Multiply it by speed.
      moveDirection *= speed;
      //Jumping
      if (Input.GetButton("Jump")moveDirection.y = jumpSpeed;                      }         turner = Input.GetAxis ("Mouse X")* sensitivity;         looker = -Input.GetAxis ("Mouse Y")* sensitivity;         if(turner != 0){             //Code for action on mouse moving right             transform.eulerAngles += new Vector3 (0,turner,0);         }         if(looker != 0){             //Code for action on mouse moving right             transform.eulerAngles += new Vector3 (looker,0,0);         }         //Applying gravity to the controller         moveDirection.y -= gravity * Time.deltaTime;         //Making the character move         controller.Move(moveDirection * Time.deltaTime);     } }