Ok got it. There are 3 different types of screws that came with the case, and I can't really figure out which one to use because the manual doesn't say. But after portioning them out, I see one type of screw only came with 4 of them, so it must be that one, it looks like it has a washer connected to the bottom of the head of the screw?
Also, I thought the motherboard could shorted out if it touches metal? I'm just curious about this, as I am sure the makers of the case and motherboard have taken this into consideration