Have you got a system to install linux on? That is the best place to start. Basic configuration of an ethernet adapter is handled by most distros during install. Try turning it into a server. Add a wireless adapter, and figure out how to configure it. Adding an adapter after you install will help you learn about finding and installing KLM's ( drivers ). Lots of people struggle with wireless, just scan through the forum.
For the server part, it all depends on what you might be interested in. Samba FTP SSH NFS web servers. Just some thoughts. There are HowTo's if you google for each. Best part with linux is its all there.