Question Help me Flappy Bird Fans

So im currently making a flappy bird game (for practice) and im having a little bit of an issue when i try to use velocity and stuff it wont show when i put the script on my character... please help me i want to learn

This is what i want to do:



this is my code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Character : MonoBehaviour {
6.  
7.     public Rigidbody2D rb;
8. public float moveSpeed;
9. public float flapHeight;
10. public GameObject pipe_up;
11. public GameObject pipe_down
12.  
13.    
14.     void Start() {
15.         rb = GetComponent<Rigidbody2D>();
16.  
17.  
18.     }
19.  
20.    
21.     void Update() {
22.  
23.         rb.velocity = new Vector2(moveSpeed, rb.velocity.y);
24.  
25.         if (Input.GetMouseButtonDown(0))
26.         {
27.             rb.velocity = new Vector2(rb.velocity.x, flapHeight);
28.         }
29.  
30.         if (transform.position.y) > 18 || transform.position.y < -19)
31.        {
32.             Death();
33.        }
34.  
35.      }
36.  
37.     public void Death()
38.     {
39.         rb.velocity = Vector3.zero;
40.         transform.position = new Vector2(0, 0);
41.  
42.  
43.     }
44.