How to check if file already exists in the folder

Dim SourcePath As String = "c:\SomeFolder\SomeFileYouWantToCopy.txt" 'This is just an example string and could be anything, it maps to fileToCopy in your code.
Dim SaveDirectory As string = "c:\DestinationFolder"

Dim Filename As String = System.IO.Path.GetFileName(SourcePath) 'get the filename of the original file without the directory on it
Dim SavePath As String = System.IO.Path.Combine(SaveDirectory, Filename) 'combines the saveDirectory and the filename to get a fully qualified path.

If System.IO.File.Exists(SavePath) Then
   'The file exists
Else
    'the file doesn't exist
End If