First of all, where is/was the switch?
Where does the red wire, connected to the gold terminal of the receptacle, come from? A switch or the breaker?
The wire connected to the silver terminal of the receptacle should be white, not red, and connected with the other neutrals.

You would not want the receptacle to be controled by the photosensor. Its amperage rating is not sufficient.

To install the photosensor, its black lead connects to the hot leg from the breaker panel. The white lead connects to the neutrals from both the panel and the lights. The red lead connects to the hot leg going to the lights.
I would have a switch on the hot (black) lead going to the photosensor in order to turn the lights off should they occasionally be not wanted on after dark.

Ok, the switch was to the left of the outlet. The red wire went to it and I believe the white wire was with it (on the same terminal).

So, Im still really confused. The black wires together in the back remain by themselves? I should remove the short red wire and replace the other red one with the white from the breaker?

I want the outlet to remain there, but would it be easier to simply remove it at this point?

Sounds like you took things apart without taking notes or pictures.

At this point, I'm afraid you are probably in over your head. You could pick up a copy of Wiring Simplified at the library, bookstore, or even Home Depot, and spend a few days reading and studying. Then you'd be at least somewhat better prepared to work out where to go from here. But you might be better off to call in a pro to sort things out.

Ok, thank you. I wanted to take a picture before I started, but forgot in the excitement of my little project. I really thought it would be fairly simple. Thank you for your help and advice!

CAUTION: Black wire is 120 volts, so turn off breaker before attempting.

Here are the wiring instructions:

Sensor's black wire connects to black wire coming from house

Red sensor wire connects to light's black wire .

All 3 white wires (house, sensor and light) are connected together.