Wiring the photo sensor and the electrically operated solenoid valve is not extremely complex, but it does require some skill and experience with electricity. If you don't have these skills, don't try this on your own.
To connect these components, wire the sensor and the solenoid valve controller to either a DC or AC power supply. Place the photo sensor where you expect people to arrive, like at the top of your porch stairs. When someone walks in front of the photo sensor, the prop will automatically move without you having to stand there waiting.