Well, for Croagunk, you'd log in and there should be two orange boxes on the lower right side, click the top one. Then a box with three options should come up... the one that says 2010-10-20 is Croagunk. Enter the password from there. For Kanto starters, I'm guessing it's the one that says 2010-09-18?
Thanks. :) So, the password I got was fake. I just read somewhere that the serial numbers aren't static, so I'm going to have to hunt down a copy of Pia. :( Also, I just got the Croagunk, but do I have to encounter the Croagunk in the Dream World still, or is it automatically going to be sent to my game?