Automatic code to execute only if certain cell is empty

Hi.
Not sure what i'm doing wrong here but excel is sending me an error message. Basically what i'm trying to do is have an automatic code run only if a certain cell is empty, see below ( i made the font red where the code error refers to):

Private Sub Worksheet_Change(ByVal Target As Range)
If Range("AU26") = "" Then
    If Target.Address <> "$F$14" And Target.Address <> "$E$3" And Not Target.Column > 12 Then
        On Error GoTo ErrHandler
        Application.EnableEvents = False
        Target.Formula = UCase(Target.Formula)
    End If
    
    If Target.Address(0, 0) = "E3" And Target.Value <> "" Then
        Target.Value = Application.WorksheetFunction.Proper(Target.Value)
    End If
    
    If Target.Address(0, 0) = "F8" And Target.Value <> "" Then
    Range("D22").Value = Target
    End If
    
    If Target.Address(0, 0) = "F10" And Target.Value <> "" Then
    Range("D23").Value = Target
    Range("N8").Value = Target
    Range("N8").Value = Application.WorksheetFunction.Proper(Range("N8").Value)
    End If
    
    If Target.Address(0, 0) = "F12" And Target.Value <> "" Then
    Range("D23").Value = Range("F10") & " " & Target
    Range("N8").Value = Range("F10") & " " & Target
    Range("N8").Value = Application.WorksheetFunction.Proper(Range("N8").Value)
    End If
    
    If Target.Address(0, 0) = "N8" And Target.Value <> "" Then
        Target.Value = Application.WorksheetFunction.Proper(Target.Value)
    End If
        
ErrHandler:
        Application.EnableEvents = True
        End If
End Sub

Try like this:

Private Sub Worksheet_Change(ByVal Target As Range)
If Me.Range("AU26").Value = "" Then
    If Target.Address <> "$F$14" And Target.Address <> "$E$3" And Not Target.Column > 12 Then
        On Error GoTo ErrHandler
        Application.EnableEvents = False
        Target.Formula = UCase(Target.Formula)
    End If
    
'and rest of the code here
        
ErrHandler:
        Application.EnableEvents = True
        End If
End Sub

That did the trick. Thanks!
Can you give me a brief explanation what the me.range did?
This is new to me.