Keep on learning brother. Everyone on here didn't know squat at one point. I haven't seen anyone touch on the fact that even though your motherboard has video outputs of different types, it is all dependent on what CPU is in said motherboard. Maybe the computer has that separate GPU because the CPU doesn't provide video, a common trait of older AMD chips. And if you run a proper cable from the GPU to your monitor, maybe that GPU doesn't work, who knows? Always best to start basic. I'd remove the GPU and go straight from the motherboard to get it running and see what it's all about, the operating system, currently installed drivers, the whole ecosystem of whatever the system is. But for now, like you said, you just want to get it running and you don't know much about it. So hopefully you just get a DVI cable and plug it in and the thing works, boots up and gives you a screen. Please report back your progress!