Old Dog learning new tricks

I am a 52 yr old male and I just bought my 2nd Apple product. First was an ipad mini 3 mo ago. Paid a bunch for the little booger. Worth every penny though. Not the device, rather the distraction the device afforded. I had a Bad Windows infection for a year spanning 2- providers, tore up 7 Windows based desktops, 3 laptops, 3 Cell phones, killed a bunch of brain cells, got measured for a straight jacket numerous times. I know, "How does anyone stay infected for a year?" Easy, "Your remote hackoff lives 8 miles from your house and is fluent in C++, Visual Studio, Python and Android platforms, has no kids or wife and you are his life, his joy".

Anyhow, good folks at Dell put the 4th Motherboard and hard drive in my oldest brand new Inspiron 620 and said they were done and asserted, "This is NOT a DELL Problem!" Well, I beg to differ... (They knew all along a hackoff was tearing up their warrantied desktops, laptops, MB's, HDDs) Dell couldn't stop the continuity inherant in cash, numerous Wal-mart locations, a robust 15 day return period (yes, I always told Wal-Mart the returns were infected), and a 1 yr Dell warranty that views my type such an exception that the warranty had no need for one, "exception", that is. Put em all together it may not be "a Dell Preoblem". Sure is a problem for Dell though. The hackoff tries to mess with the ipad (he affects it but he can't infect it) nothin sticks to it. The reset to factory default amuses me as much as it annoys him.

I didn't want to bring the newly salvaged Dell Tower case online until AT&T gave me a static external ip and did a port swap in their neighborhood client box. Even at that I bought a Ghinny Pig $40.00 Dell on craigslist. POOF! Took him 2 whole days to find the Ghinny runnin' XP Home Service pack 3. It was like a premature spill, if ya know what I mean. Fun was over as it started for him.

And then it happened..... as I was browsing those $40.00 beauties on Craigs again, A 1900 somethin Apple Power Mac G4. Like, 60 lbs I think. I LOVE THIS THING! And to think I was seriously considering a new Mac. I don't think I'm ready for that yet. This thing has like 2 gigs ram and a 80 gig hdd, dual processor. It was used as a print server. Hdd almost full. Runs as good as a 4 gig ram, 1Terabyte hdd, Intel Core I3 Dell. Albeit a bit louder. Better fan is all. No sign of hackoff at all. So, how can I update this thing. Nothin' newer than like, 2009 on it. I think it's running OS X Server? How can i know for sure? Is there anything better available for it? But first, how do I get some of the drive freed up? It's got a mirrored raid set up on the hdd. I don't know what I can delete and what i can't. Is it safe to use a server OS as a desktop? Upgrade the internet connection? Switch to different OS X? Can I up the ram? How can an old dog learning new tricks teach another old dog some new tricks? Using G4 for? I mostly use a word processor and surf the net. Any guidance is greatly appreciated.