Its not going to be handed to you as I originally stated, its a learning experience.
Even if I did send it to you prepacked you would still need to reset the directories so RetroArch can see the contents because on first run it detects and sets up its dependencies and the like to where you have it located.
RetroArch does way more than PSX, its basically your one stop shop for everything thats not PS2/GC/Wii.
If you didn't pay the devs or anyone then its not going to be as simple as one click, if you want it you need to understand it.
I'm more than happy to help those who wish to learn .