How to have Database of Dictionary elements with online images???

Hi guys, I'm new in Unity and I have this kind of problem. I'm doing Android/iOS game similar to Higher Lower Game where you compare 2 elements. My goal is to have databese of elements and when player is online be able to show image attached to element. I want to have 2 modes: when i click first button in first scene, second scene will be loaded and i will compare for example speed of element and when i click second button ,second scene will be loaded but i will compare price of element. I suppose i should use JSON and give my photos to dropbox and somehow shere them to game is this good idea or it's total rubbish? Now i have dictionary with key and 2 values, float and sprite. Part of my GameManager script. Thanks for answers. using System.Collections; using System.Collections.Generic; using UnityEngine; using System.Linq; using UnityEngine.UI; using System; using UnityEngine.SceneManagement;

 public class ListManager : MonoBehaviour {
 public Image carImage1;
     public Image carImage2;
     public Image carImage3;
 
     public Sprite lamborghiniVeneno;
     public Sprite bughattiVeyron;
     public Sprite mcLarenP1;
     public Sprite mcLarenF1;
     public Sprite porscheCarera;
     public Sprite henneseyGT;
 
 private string randomKey1;
     private string randomKey2;
     private string randomKey3;
     private float randomValueSpeed1;
     private float randomValueSpeed2;
     private float randomValueSpeed3;
     private Sprite randomValueImage1;
     private Sprite randomValueImage2;
     private Sprite randomValueImage3;
 
  Dictionary<string,ValueAndSpriteClass> database = new Dictionary<string, ValueAndSpriteClass>();
 
 private class ValueAndSpriteClass
     {
         public float carSpeed { get; set; }
         public Sprite carImage { get; set; }
     }
 public void AddToDatabase()
     {
         database.Add("Lamborghini Veneno",new ValueAndSpriteClass { carSpeed=440,carImage=lamborghiniVeneno});
         database.Add("Bughatti Veyron", new ValueAndSpriteClass { carSpeed = 420, carImage = bughattiVeyron });
         database.Add("Porchce Carera", new ValueAndSpriteClass { carSpeed = 400, carImage = porscheCarera });
         database.Add("Hennesey GT", new ValueAndSpriteClass { carSpeed = 460, carImage = henneseyGT });
         database.Add("MCLaren P1", new ValueAndSpriteClass { carSpeed = 370, carImage = mcLarenP1 });
         database.Add("MCLaren F1", new ValueAndSpriteClass { carSpeed = 430, carImage = mcLarenF1 });
     }
 
 private void ChangeRandomElement1()
     {
         var rnd = new System.Random();
         var randomEntry1 = database.ElementAt(rnd.Next(0, database.Count));
         randomKey1 = randomEntry1.Key;
         randomValueSpeed1 = randomEntry1.Value.carSpeed;
         randomValueImage1 = randomEntry1.Value.carImage;
         database.Remove(randomKey1);
         if (randomKey3 != null)
         {
             database.Add(randomKey3, new ValueAndSpriteClass { carSpeed = randomValueSpeed3, carImage = randomValueImage3 });
         }
         Debug.Log(randomKey1 + randomValueSpeed1);
     }
 
     private void ChangeRandomElement2()
     {
         var rnd = new System.Random();
         var randomEntry2 = database.ElementAt(rnd.Next(0, database.Count));
         randomKey2 = randomEntry2.Key;
         randomValueSpeed2 = randomEntry2.Value.carSpeed;
         randomValueImage2 = randomEntry2.Value.carImage;
         database.Remove(randomKey2);
         if (randomKey1 != null)
         {
             database.Add(randomKey1, new ValueAndSpriteClass { carSpeed = randomValueSpeed1, carImage = randomValueImage1 });
         }
         Debug.Log(randomKey2 + randomValueSpeed2);
     }
 
     private void ChangeRandomElement3()
     {
         var rnd = new System.Random();
         var randomEntry3 = database.ElementAt(rnd.Next(0, database.Count));
         randomKey3 = randomEntry3.Key;
         randomValueSpeed3 = randomEntry3.Value.carSpeed;
         randomValueImage3 = randomEntry3.Value.carImage;
         database.Remove(randomKey3);
         if (randomKey2 != null)
         {
             database.Add(randomKey2, new ValueAndSpriteClass { carSpeed = randomValueSpeed2, carImage = randomValueImage2 });
         }
         Debug.Log(randomKey3 + randomValueSpeed3);
     }
 }