You must configure your network card. I don't know Mandrake so I don't know where you should click to to that. But it is probably in the documentation of mandrake somewhere.
You will need to know the name of your machine ("host name") (maybe you can just invent one), the IP of the router and of the Name Server (these both are the most important). In order to know these IP adresses and the name of your machine, contact your LAN Administrator.
Most probably, you will get the IP of your machine dynamically (choose "Configure via DHCP").
The domain name does not really matter, I believe.
If you run gnome or another desktop environement, it must be something similar. But yast2 will probably not be available.
Hope this helps.