(Help) I am having trouble with creating a simple 2D game in Unity. Please help. :)

Hello all, I have just started using Unity and C# and I have been trying to create a 2D game however I am having trouble making the player shoot in the direction that they are walking and I am hoping someonw could help me with this. In addition I was hoping to add the ability to press a button and be able to shoot upwards as well. Many Thanks, Josh. The scripts : PlayerController:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PlayerController : MonoBehaviour
 {
     public float speed;
     Rigidbody2D rb;
 
     // Start is called before the first frame update
     void Start()
     {
         rb = GetComponent<Rigidbody2D>();
     }
 
     // Update is called once per frame
     void Update()
     {
         
     }
 
     void FixedUpdate()
     {
         float move = Input.GetAxis("Horizontal");
         rb.velocity = new Vector2(speed * move, rb.velocity.y);
     }
 }

Weapon:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Weapon : MonoBehaviour
 {
     public Transform firePoint;
     public GameObject bulletPrefab;
 
     // Start is called before the first frame update
     void Start()
     {
 
     }
 
     // Update is called once per frame
     void Update()
     {
         if (Input.GetButtonDown("Fire1"))
         {
             Shoot();
         }
     }
 
     void Shoot()
     {
         //shooting logic
         Instantiate(bulletPrefab, firePoint.position, firePoint.rotation);
     }
 }

Bullet:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class bullet : MonoBehaviour
 {
 
     public float speed = 20f;
     public int damage = 40;
     public Rigidbody2D rb;
     public GameObject impactEffect;
 
     // Use this for initialization
     void Start()
     {
         rb.velocity = transform.right * speed;
     }
 
     void OnTriggerEnter2D(Collider2D $$anonymous$$tInfo)
     {
         Health enemy = $$anonymous$$tInfo.GetComponent<Health>();
         if (enemy != null)
         {
             enemy.TakeDamage(damage);
             if (damage == 100)
             {
                 Destroy(gameObject);
             }
         }
 
         Instantiate(impactEffect, transform.position, transform.rotation);
 
         //Destroy(gameObject);
     }
 
 }