If my cat is on range of sensor (like 80cm) the activate the water pump in a fountain.
Shouldn't be too hard.
I dont know about the wires position on protoboard and the code in arduino.
I would suggest working through some of the examples in the IDE: Blink without delay() , then read up on driving relays using transistors: Playground>Interfacing with Hardware> Output> electrical/high power, then check out the New Ping library for ultrasonic sensors found in the Sensors section of the forum, and finally combine sketches. Post what you have so far and you will probably get more help.