Start by contacting the ones you do know and inquiring as to the status, balance, etc. Next go to
www.annualcreditreport.com and request your free credit reports from the three major credit bureaus. Those will list any accounts which have reported, whether its current, past due, in collections, charge off, whatever, and the name and address of the creditor reporting the information as well as the last reported balance.
You maybe in for a lot hard, and sometimes frustrating work.
Please register for this site, and come back. Post your questions, experiences so that others may benefit from your experiences. WE have a great community that is willing to help in any way they can, and sometime just provide some much needed moral support.