I installed glassfish v3 some time ago and it's been a while since I last used it, so I forgot the port on which the server is listening and the port on which the admin console is listening. Moreover, i forgot the admin password!
I'm pretty sure I've change them because I've tried the default values and didn't work.
Is there any configuration file where I can look for them (at least the port numbers)?
will give you all the listening ports, so you can start from there.
The default port for admin console is normally 4848.
Check the domain.xml file under the config dir in your Glassfish Domain.
And for overriding password, refer to http://docs.oracle.com/cd/E19776-01/820-6823/abgdh/index.html.