RTS Unit Creation Bar Queue System

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class Queue : MonoBehaviour {
 
     //void Awake()
     //{
         List <GameObject> BarracksQueue = new List<GameObject> ();
     //}
 
     class TroopBuilderJob //Can go in its own script, or the bottom of another script.
     {
         public enum ToBeBuilt {Infantry}; //Make a public Enum including your troop types.
 
         public int AmountToBeBuilt = 0; //The amount of the troop type to be built.
     }
 
 
     void Update()
     {
          Queue<TroopBuilderJob> TroopBuilderQueue = new Queue<TroopBuilderJob>(); //This will hold your build queue. You'll want to loop through this and pull info from it.
 
 
         bool UseExisting = false; //Use existing TroopBuilderJob?
         foreach (TroopBuilderJob i in Queue.BarracksQueue)
         {
             if (i.ToBeBuilt == Infantry) {
                 //If an existing TroopBuilderJob exists, we'll use it instead of making a new one.
                 i.AmountToBeBuilt++; //Adding the amount by 1.
                 UseExisting = true; //Sets the "UseExisting" to true.
             }
         }
 
         if (!UseExisting) {
             //Since no previous build job matches the troop type we're attempting to make..we're going to make a new one.
             TroopBuilderJob tb = new TroopBuilderJob ();
             tb.ToBeBuilt = Infantry; //Set this to the type of unit you're building.
             tb.AmountToBeBuilt = 1; //I assume you're going to increment by 1.
             Queue.BarracksQueue.Add (tb); //Adds the newly created TroopBuilderJob to the master list...which you will parse through.
         }
     
     }
 }

That's what I got so far in one script and its not working too well because theres errors everywhere what am I doing wrong..

I understand your frustration. But it looks like you don't understand the simplest of c#. I'm not going to write your script for you. I've done more than enough as is. I suggest you learn more core coding before you continue.