oof! how did I miss this??
If you want to make a career of it then you have to go the server route. Red Hat or SUSE.
We use loads of Linux servers at work - all SUSE. I use openSUSE on my desktop at work.
To start off with, do as you are doing and get a copy installed to play around with, ideally two versions so you can get used to the networking. Then get into Apache, PHP, MySQL, (from a installing and configuring point of view - not really programming).
Try to get in to using the command line as much as possible and have a look at shell scripting.
THat should keep you going for a while!
