Beginner doing an OOP Project vb.net - vb.net

Question

Alright, so I have edited my code and now when I'm trying to run it I'm getting this error.
An unhandled exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll
Additional information: Conversion from string "Holden 308" to type 'Integer' is not valid.
Additional information: Conversion from string "JD Catepillar Track" to type 'Integer' is not valid.
So both errors are happening in the HeavyStockItem class with the overloading New classes. Wondering if anyone can help me out with understanding why it's doing that.
Option Strict On
Public Class Form1
Dim StockItem1 As StockItem
Dim StockItem2 As CarEngine
Dim StockItem3 As CarEngine
Dim StockItem4 As StockItem
Dim StockItem5 As HeavyStockItem
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
StockItem1 = New StockItem("Screwdriver Set", 42)
StockItem2 = New CarEngine(8025, "Madza B6T", 1252, 800, "Z4537298D")
'StockItem3 = New CarEngine("Holden 308", 958, 1104, "P74623854S")
StockItem4 = New StockItem(8002, "Trolley Jack", 127)
'StockItem5 = New HeavyStockItem("JD Catepillar Track", 3820, 2830)
End Sub
Private Sub btnListStock_Click(sender As Object, e As EventArgs) Handles btnListStock.Click
txtOutput.Clear()
ShowOutput(StockItem1)
ShowOutput(StockItem2)
'ShowOutput(StockItem3)
ShowOutput(StockItem4)
'ShowOutput(StockItem5)
End Sub
Public Sub ShowOutput(ByVal Output As StockItem)
txtOutput.Text &= Output.Print()
txtOutput.Text &= vbCrLf
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btnEnd.Click
End
End Sub
End Class
Public Class StockItem
Friend CostPrice As Integer
Friend LastStockNumber As Integer
Friend StockNumber As Integer
Friend Description As String
Friend Shared LastStockItem As Integer = 10000
Overridable Function Print() As String
Dim Result As String = ""
Result &= "Stock No: " & StockNumber
Result &= vbCrLf
Result &= "Description: " & Description
Result &= vbCrLf
Result &= "Cost Price: " & CostPrice
Result &= vbCrLf
Return Result
End Function
Public Sub New(ByVal StockNumber As Integer, Description As String, ByVal CostPrice As Integer)
Me.New(Description, CostPrice)
Me.StockNumber = StockNumber
End Sub
Public Sub New(ByVal Description As String, ByVal CostPrice As Integer)
LastStockNumber += Rnd()
Me.StockNumber = LastStockNumber
Me.Description = Description
Me.CostPrice = CostPrice
End Sub
Public Sub GetCostPrice()
End Sub
End Class
Public Class HeavyStockItem
Inherits Assessment3.StockItem
Friend Weight As Integer
Public Function GetWeight() As String
Return Me.GetWeight
End Function
Public Sub New(ByVal StockNumber As Integer, ByVal Description As String, ByVal CostPrice As Integer, ByVal Weight As Integer)
MyBase.New(StockNumber, Description, CostPrice)
Me.Weight = Weight
End Sub
Public Sub New(ByVal Description As String, ByVal CostPrice As Integer, ByVal Weight As Integer)
MyBase.New(Description, CostPrice, Weight)'' Where the error is occurring
LastStockNumber += Rnd()
Me.StockNumber = LastStockNumber
End Sub
End Class
Public Class CarEngine
Inherits Assessment3.HeavyStockItem
Friend EngineNumber As String
Overrides Function Print() As String
Dim Result As String = ""
Result &= "Stock No: " & StockNumber
Result &= vbCrLf
Result &= "Description: " & Description
Result &= vbCrLf
Result &= "Cost Price: " & CostPrice
Result &= vbCrLf
Result &= "Weight: " & Weight
Result &= vbCrLf
Result &= "Engine Number: " & EngineNumber
Result &= vbCrLf
Return Result
End Function
Public Sub New(ByVal StockNumber As Integer, ByVal Description As String, ByVal CostPrice As Integer, ByVal Weight As Integer, ByVal EngineNumber As String)
MyBase.New(StockNumber, Description, CostPrice, Weight)
Me.EngineNumber = EngineNumber
End Sub
Public Sub New(ByVal Description As String, ByVal CostPrice As Integer, ByVal Weight As Integer, ByVal EngineNumber As String)
MyBase.New(Description, CostPrice, Weight)
LastStockNumber += Rnd()
Me.StockNumber = LastStockNumber
End Sub
End Class
Any help provided would be great. Just thought it'd be easier to provide the full code instead of just putting only the little bits that I really needed, incase if people asked about the other parts of the code. Thanks for reading and providing help if you provided help.

Answer 1

Since your code was confusing to me I relied mostly on the exception.
It basically says that it cant convert the string into an integer. Here's something that could cause the same problem.
Dim Number As String = "10"
'Few Lines of code.
Number = 11
whats basically happening is that when you declare a variable as a string the value of it HAS to be in double quotes as you see when it was declared. Now then we try to change the value to 11 while adding no double quotes, therefor it thought you were changing it to an integer and gave the error.
I looked through the code and saw this, maybe this is causing it:
Me.Description = Description <--- No quotes!!!
I'm probably wrong though since i didn't really understand the code.