The fare rules appear in several places. First one is right at the screen before you are supposed to hit Purchase or Hold, and the second place would be at the payment screen right below the line with the price at the top of the screen there's the link for the Fare rules. Since you've already purchased two tickets the way to find out the fare code is by going to http://www.refunds.aa.com and entering either your PNR and Last Name or your Ticket Number or Last Name. On the next screen you will see a list of your flights and also the fare basis for each flight. Needless to say, do *NOT* go past that initial screen on the refund process...
And of course the other way to find out the fare code is by calling AA and asking

Regards,
Chris