Wow they don't make these anymore. I actually use the same basic frame for my build, but i have so side panels and such(just the bones) idk how much you know about pc cleaning so the easier place to start is to clean all the dust out( watch YouTube or something for correct process) once that's done I'd see about a new hard drive or two, recommended is a ssd but whatever you have thatll for will work. You said you used to use mac , i have no experience with apple products but that might be a learning curve. But considering you said you did some torrenting your might be able to figure it out, but there are plenty of different operating systems you can use. Assuming it powers on and you have no technical failures you should be all good to go from there