How to make my space ship shooting (2D Game)?

Hi, (I'm a beginner) I wrote this script for space ship:

 using UnityEngine;
 
 public class ShipController : MonoBehaviour {
 
 
     public GameObject bullet;
     private int speed, speed2;
     public float x, y;
     public float maxSpeed = 200f;
 
 
 
     void Start () {
         bullet.SetActive(false);
         speed = 2;
         speed2 = 2;
         x = transform.position.x;
         y = transform.position.y;
     }
 
     void Update() {
 
 
 
         var rigidbody = this.GetComponent<Rigidbody2D>();
 
 
 
         if (Input.GetKey(KeyCode.W))
         {
             rigidbody.AddRelativeForce(Vector2.up * speed);
         }
         if (Input.GetKey(KeyCode.S))
         {
             rigidbody.AddRelativeForce(Vector2.up * -speed);
         }
         if (Input.GetKey(KeyCode.A))
         {
             rigidbody.AddTorque(speed2, ForceMode2D.Force);
         }
         if (Input.GetKey(KeyCode.D))
         {
             rigidbody.AddTorque(-speed2, ForceMode2D.Force);
         }
         if (Input.GetKey(KeyCode.Q))
         {
             rigidbody.AddRelativeForce(Vector2.left * speed);
         }
         if (Input.GetKey(KeyCode.E))
         {
             rigidbody.AddRelativeForce(Vector2.right * speed);
         }
         if (Input.GetKey(KeyCode.LeftShift) && rigidbody.velocity.magnitude <= 2)
         {
             rigidbody.velocity = rigidbody.velocity.normalized * 0;
         }
 
 
 
         if (rigidbody.velocity.magnitude > maxSpeed)
         {
             rigidbody.velocity = rigidbody.velocity.normalized * maxSpeed;
         }
 
 
 
         var bullet_rigbody = bullet.GetComponent<Rigidbody2D>();
 
         bullet.transform.rotation = this.transform.rotation;
     }
 }
 

And this for bullet:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Bullet : MonoBehaviour {
 
     public GameObject ship;
 
     void Start () {
         gameObject.SetActive(false);
     }
     
 
     void Update () {
         var bullet_rigidbody = gameObject.GetComponent<Rigidbody2D>();
         if (Input.GetKeyDown(KeyCode.Space))
         {
             gameObject.SetActive(true);
             gameObject.transform.rotation = ship.transform.rotation;
             gameObject.transform.position = ship.transform.localPosition;
             bullet_rigidbody.AddRelativeForce(Vector2.up * 400);
         }
     }
 }
 

Problem: bullet is not displaying while i press space. Please help. PS: How to destroy object when I shoot this object?