I'm just getting started with Inkscape and other Open Source software, and some I find confusing because the instructions are "over my head"!

I have Inkscape downloaded and installed, and it seems to run. I want to import some WMF files, and I get a message I need to have Uniconvertor installed. I can't seem to find a Mac package for Uniconvertor, only Windows and Linux. Is there a Mac version somewhere, and if not, any suggestions as to how to get around this limitation? I'm fairly new to Macs as a regular user, so possibly there is some other open source convertor that may work.
I haven't downloaded and printed any documentation as of yet. Mostly, because my printers are out of toner and/or ink!

Could someone point me to an "X Windows for Dummies" type of page? Wikipedia's info is outside my understanding at the moment.
I think that's all at the moment.