Nooo, you don't buy PSP games for an emulator. They are disks, but they're in a container where you can't get the disc out (without ruining it) to put in your computer or anything. You have to find a site that lets you get ROMs or ISOs, or torrent them. For PSP games they're sometimes called CSO (Compressed ISO) and then use those in the emulator. I'm not sure if I can go into much more detail without getting into trouble, because though most gamers use emulators at some point in their life, it's kinda illegal and sort of has to be "officially" frowned upon by anyone helping run the site, or they'll get in trouble for supporting piracy