The Core2Duo is very old by now, and is going to hamper performance significantly, but even more important is the fact that you can't get any kind of capable graphics card for that price.
This is about the best graphics card you're going to find near 80 dollars.
http://pcpartpicker.com/part/zotac-video-card-zt7070110m
And that or the R7 360 are the lowest model cards I'd honestly recommend gaming on if you don't want to just be frustrated.
What is the model of the Core2duo you can get for free? You need to understand that a lot of games now won't even let you install or play them if they don't detect at least a quad core CPU.