problem with read a .txt and save the words in an array

Hi everyone. I'm making a card game and i need read a .txt file to get the hability information of each card but i have a problem when i try save the hability in an array. Somebody can help.PS This is the error (NullReferenceException: Object reference not set to an instance of an object Load_txt.ReadFromFile () (at Assets/Script/Load_txt.cs:31))

 using UnityEngine;
 using System.Collections;
 using System.IO; 
 using System; 
 using System.Runtime.Serialization.Formatters.Binary; 
 using System.Runtime.Serialization; 
 
 public class Load_txt : MonoBehaviour 
 {
     C_ard[] card=new C_ard[3];
     void Update()
     {
         ReadFromFile();
     }
 private void ReadFromFile()
 {
 
         int cont=0;
         StreamReader read=new StreamReader(@"C:\Users\Julio\Desktop\Jogo\Trunfo\Nova Pasta\Super Trunfo - Os Vingadores\A\captaoamerica.txt");
 
         string r=read.ReadLine ();
 
         while (r!=null) 
         {
             char[] charcontrol={':'};
             string[] fields=r.Split(charcontrol);
 
 
 
             for (int i = 0; i < card.Length; i++) 
             {
         
             card[0].id=fields[0];
             
                 if (card[0].id=="A2") 
                 {
                     Debug.Log("capitao america");
                 }
             }
             r=read.ReadLine();
     
     
         }
 
 }
 public class C_ard
 {
     public string id, nome;
     public int forca, velocidade, habilidade, equipamento, inteligencia;
      /*public  card(string id, string nome, int forca, int velo, int habl, int equi, int inteli)
     {
         this.id=id;
         this.nome=nome;
         this.forca=forca;
         this.velocidade=velo;
         this.habilidade=habl;
         this.equipamento=equi;
         this.inteligencia=inteli;
     }*/
 }
 }