Why cant move my character?

With this script my player when i start the game move aouto matically forward and when i press the w,a,s,d nothing happen …
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Moving : MonoBehaviour {

public  Animator anim;
public Rigidbody Rbody;

private float InputH;
private float InputV;

void Start () {
	InputV = Input.GetAxis ("Vertical"); 
	InputH = Input.GetAxis ("Horizontal");

	
	anim.SetFloat ("InputH", InputH);
	anim.SetFloat ("InputV", InputV);

	anim = GetComponent<Animator> ();
	Rbody = GetComponent<Rigidbody> ();

	float moveX = InputH * 20f * Time.deltaTime;
	float moveZ = InputV * 50f * Time.deltaTime;

	Rbody.velocity = new Vector3 (moveX, 0, speed);

}


void Update () {
	if (InputV != 0) {
		anim.SetBool ("Move", true);

	} else {
		anim.SetBool ("Move", false);
	}

	}

You’re only looking for input on the frame where Start is called.

To do it constantly, you need to move it to Update. Basically everything in your Start function should be in Update (except your GetComponents).