my enemy passes through the walls in unity ?

hello!! i am facing a problem that my enemy can pass through rocks and all the things in the game... i am currently using transform.Translate and transform.Rotate in my script. And i also know that transform.Translate avoids all the physics. To do this, i need to use Physics to move my character. However, i am very confused which one to use and how to use (coz , i am new to unity). so if anybody can help me, tell me what i should use.

here is the code i am using for enemy_movement:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class enemy_movement : MonoBehaviour
 {
      public GameObject player;
     Animator anim;
     Rigidbody rb;
     public float speed = 1.0f;
 
     // Use this for initialization
     void Start()
     {
         anim = GetComponent<Animator>();
         rb = GetComponent<Rigidbody>();
     }
 
     // Update is called once per frame
     void Update()
     {
         if (Vector3.Distance(transform.position, player.transform.position) < 25.0f)
         {
             anim.SetTrigger("isWalking");
             //transform.LookAt(player.transform);
             Quaternion targetRotation = Quaternion.LookRotation(player.transform.position - transform.position);
             transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, 1 * Time.deltaTime);
             transform.position += transform.forward * 1f * Time.deltaTime;
         }
     } 
 
 }