Welcome. I'm pretty new here myself. They didn't sell the 328 until '96... as for replacement keys, I assume you'd have to go to a dealer, and it's probably not going to be cheap. The A and M is probably either a winter/summer mode or a regular/sport mode... never been in an automatic, so that's just a relatively educated guess.
Now: '95 ///M3 JC chip & CAI, JTD under
'95 325is sport highly modified R.I.P.