another thing about times changing - virtuals are great. download some
popular distros (don't limit yourself to linux either). i'd suggest
debian, fedora, centos, ubuntu, and freebsd. then get virtual box and
have fun. go, install, snapshot and then mess everything up. if you
can't figure out how to put it back together again, revert to the
snapshot.
You'll need VMWare or VirtualBox (VBox is free but because it's not Oracle owned, it's licence might radically change without warning ... If you *really* want to make a project out of it, try Gentoo too, fair warning though, it can be time consuming.