The FileDateTime function will return the date and time the file was last
modified.

The FileLen function will return the length of the file in bytes.

Both functions take a single argument: the full path to the file.

Having said that, unless you're using really old operating systems, you
should be able to use FSO without any problems. It's not even necessary to
set a reference to it in Access: you can use Late Binding instead.

Sub UsingFSO(FilePath As String)

Dim objFSO As Object
Dim objFile As Object
Dim strOutput As String

 Set objFSO = CreateObject("Scripting.FileSystemObject")
 Set objFile = objFSO.GetFile(FilePath)
 strOutput = FilePath & " is " & objFile.Size & _
   " bytes, and was last modified " & _
   objFile.DateLastModified
 MsgBox strOutput

End Sub

For what it's worth, I rarely, if ever, use FSO. Using APIs is significantly
faster. Tests I did enumerating files on a hard drive showed using APIs to
be an order of magnitude faster than using VBA functions, and the VBA
functions were an order of magnitude faster than using FSO.