Need help on using System.Collections.Generic

Im beginner using LIST. After study the many example, so far i've have below class

public class ShoppingCartItem

//TrxNo

private int _trxNo = 0;

public int TrxNo

get { return _trxNo; }

set { _trxNo = value; }

//Order Date

private string _OrdDate = "";

public string OrdDate

get { return _OrdDate; }

private set { _OrdDate = value; }

//Product ID

private string _id = "";

public string ID

get { return _id; }

private set { _id = value; }

//Product Description

private string _Desc = "";

public string Desc

get { return _Desc; }

private set { _Desc = value; }

//Quantity

private int _quantity = 1;

public int Quantity

get { return _quantity; }

set { _quantity = value; }

//Price Per Unit

private decimal _unitPrice;

public decimal UnitPrice

get { return _unitPrice; }

private set { _unitPrice = value; }

public ShoppingCartItem(int trxno,string ordDate, string id, string desc, int quantity, decimal unitPrice, decimal subTotal)

this.TrxNo = trxno;//UniqueID

this.OrdDate = ordDate;//Order Date

this.ID = id;//Product ID

this.Desc = desc;//Product Description

this.Quantity = quantity;//Order Quantity

this.UnitPrice = unitPrice;//Price Per Quantity

this.SubTotal = subTotal;//Price Per Quantity