Need Help

Hi, i need help at my Move and Jump code:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Movement : MonoBehaviour
{
public float movementSpeed;
public Rigidbody2D rb;

public float jumpForce = 20f;
public Transform feet;
public LayerMask groundLayers;

float mx;

private void Update()
{
mx = Input.GetAxisRaw("Horizontal");

if (Input.GetButtonDown("Jump") && IsGrounded()){
Jump();

}

}


private void FixedUpdate()
{
Vector2 movement = new Vector2(mx * movementSpeed, rb.velocity.y);

rb.velocity = movement;
}

void Jump()
{

Vector2 movement = new Vector2(rb.velocity.x, jumpForce);

rb.velocity = movement;

}
public bool IsGrounded(){

Collider2D groundCheck = Physics2D.OverlapCircle(feet.position, 0.5f, groundLayers);
if (groundCheck != null) {
return true;
}

return false;
}
}
if i start i cant jump. And if I add groundCheck.gameObject there is a message coming which says that the gameobject has no instance

 

Can you edit your post and use code tags please? Difficult to read