Don't worry about the auto run yet, go to Tools - Macro - Record New Macro then do all the steps needed to accomplish your goals:
"opens a workbook, refreshes the data(it comes from an external source)sends the wb as an attachment to multiple recipients, then closes"
Once you do all the above, stop the recorder, go to Tools - Macros then edit the macro you just recorded and you will have all the code needed to do the above. then you can worry about getting it to auto open!