Try to keep track what I typed in the cell

No problem...

Try...

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim LC As Long: LC = Cells(1, Columns.Count).End(xlToLeft).Column
    Dim rng As Range
    Set rng = Target.Parent.Range("F5")
    If Target.Count > 1 Then Exit Sub
    If Intersect(Target, rng) Is Nothing Then Exit Sub
    If Target.Value = "" Then Range(Cells(1, 13), Cells(1, LC)).ClearContents
    If Range("M1") = "" Then
        Range("F5").Copy Cells(1, 13)
    Else
        Range("F5").Copy Cells(1, LC + 1)
    End If
End Sub