Hmmm...
I'd do like this:
Get X up and running in SVGA by selecting the 'xserver-svga' option.
Once X is running, i'd get hold of nvidia's linux-driver-package for the GeforceGo.
To get the Nvidia package into your system you might need to get hold of kernel sources - the installer may need it to recompile a driver module suitable for your flavour of kernel.
But first - get X going in SVGA. It's unaccelerated, but it's still X.
And then you can move on to something more interesting, like setting up printers or networking or...
Why Knoppix? Being a beginner you could profit from choosing one of the major distributions aimed at first-time-users; Fedora or Mandriva. Perhaps Ubuntu, though i haven't tried it and thus can't say much about it.
Do NOT try Debian, FreeBSD or Slackware - these are IMHO aimed at more experienced users.
Knoppix is fine for showcasing what Linux is and how it looks, but is IMHO not a 'real' installation. It's a showcase running off of a CD.
Nvidia distributes ready-to-go-drivers for eg. Fedora.
Heck, Fedora might even recognize your nvidia-gpu and install the graphics too without you needing to bother about anything.
Think about it this way; Linuxes are more or less functionally equivalent - you might as well choose one that supports your hardware directly. And if Knoppix gives you trouble, try another one.
Last words: What do Knoppix, Ubuntu, Mepis and a whole lot other distributions have in common apart from being linuxes? They're all based on Debian. Thus, mastering Debian Linux is no bad thing...
But save it for later, when you are more confident with Linux as a working platform.
Very last words: Commercial vendors like Redhat and Mandriva offer small, medium and large versions of Linux. No such thing exists - only more or less limited versions. Look to Debian & Co. for a more realistic approach to 'whats in the package'
Everything - all the time.