Reverse lights and tailight wiring

[Camy13588]

So I bought a 2015 4x4 SLT sierra (1500) on the 3rd of January. On my test drive I engaged the right turn signal and after a couple flashes it started hyper flashing. Stupid me assumed it was just a bulb and didn’t worry too much about it. On the drive home my buddy who was following me home calls me and says there no turn/tail or brake lights on the passenger side and there’s also no reverse light . Now that I finally got some time off work I took the light housing off and came to find the bottom light socket completely cut out and missing. Not sure why anyone would do this especially with the fact that where I bought it from was a certified used car dealer (3 hours away in another province) and had just put on a fresh inspection sticker. My question being does anyone know the part number to the socket? And also my driver side reverse light does not work, but I’m wondering are the two reverse lights for each side in the same circuit causing the driver side to not work since there’s no power at the passenger side? Thanks