So I put in a new bulb in the socket and of course no light but the other side worked perfectly when I put in new bulb. The inside of the socket was a little rusty and crusty how do I fix it to get it to turn on
Follow the wiring from inside the fender, it usually goes to a plug that connects to the front wiring harness and travels across the front of the car. Make sure the bulb has good clean contact and the connector is nice and clean also.
First check if there's power at the socket. Put sandpaper on the tip of a screwdriver and sand the contacts inside the socket until they shine again. Use a product like WD-40 contact cleaner spray: