You will also need to install a "base development system" to be able to compile. I don't know what "Foresight Linux" installs by default, so it is kind of tough to tell you what to install.
I'm assuming that the package manager is smart enough to already install the correct version of GTK if you install wxGTK (but even this isn't granted for sure, of course).
Considering that you ask "how does one compile stuff in Linux", I am afraid that this may turn into a never ending nightmare for you. Maybe you want to install a more "mainstream" distribution (try Ubuntu) on another partition and try that first, following the step-by-step documentation.
That way, you get an idea and the "feeling" how things work at all, and you may be able to build on "Foresight Linux" later.