Enemy AI Not Working?

This is my first time attempting Enemy AI and I have no idea if I'm doing it right. This code doesn't work and I just need to be told what I'm doing wrong and how I can fix it:

 using UnityEngine;
 using System.Collections;
 
 public class Enemy : MonoBehaviour {
 
     private Animator animator;
     private GameObject player;
     private GameObject enemy;
     private float range;
     public float speed;
 
     public bool grounded;
     public Transform groundCheck;
     float groundRadius = 0.2f;
     public LayerMask whatIsGround;
 
 
     // Use this for initialization
     void Start () {
         player = GameObject.FindGameObjectWithTag("Player");
         enemy = GameObject.FindGameObjectWithTag("Enemy");
         speed = 5f;
     }
     
     // Update is called once per frame
     void FixedUpdate () {
         isGrounded();
     }
 
     void Update()
     {
         range = Vector2.Distance(enemy.transform.position, player.transform.position);
 
         if (range <= 15f)
         {
             transform.Translate(Vector2.MoveTowards(enemy.transform.position, player.transform.position, range) * speed * Time.deltaTime);
         }
     }
 
     void isGrounded()
     {
         grounded = Physics2D.OverlapCircle(groundCheck.position, groundRadius, whatIsGround);
         animator.SetBool("Ground", grounded);
     }
 }