so I recently replaced my driver side blinker socket since neither my parking light or blinker were working. Now that I have replaced the socket, the parking light works but the blinker does not. The passenger side works OK. What am I missing ??

 

Do you have anything like a test light or voltmeter to use ?
Either one could tell you if the signal is getting to the socket.

Where did you connect the third wire from the replacement socket ?

 

1157 bulb with dual filament.
Black - ground
White - parking light
Red - brake + blinker

If you reversed the white and red then you have to turn on the parking light during day time to verify if those 2 wires are really reversed. And parking light is much dimmer you know that.