Back up camera for '12 Versa Hatchback

I have a 2012 Nissan Versa Hatchback that does not currently have a media screen or a back up camera. I want to buy a media screen/back up camera kit for my car, and take it to somewhere like best buy for them to install. Does anyone know which specific equipment I need to buy for my car? I don't know what fits it or the size I would need, etc. I want an in dash media screen for the back up camera.