Everything that you need to know about running the sample apps in the AIK is in the documentation.
As long as you have put data.zip into the drop-in deployer, deployed the sample apps, and configured them to use the certs as described in the doc via configuration.jsp, it works.
If you're asking what the default user/password of PingFederate is for the admin console, then it is administrator/2Federate .
Anything above that, though, and I'm going to need better information to help you.