I Need some serious help

https://uk.pcpartpicker.com/guide/xfmPxr/i5-4460-gtx-960-gaming-pc Use this build guide, but instead of the crappy Corsair PSU suggested get an XFX TS 550W or a Seasonic equivalent, as they will be better quality and more reliable and efficient. This will be able to handle GTA V at 1080p, but maybe not with MSAA enabled. I would suggest using FXAA in the nVidia control panel instead, so you get smoother and less pixelated edges without compromising too much performance.