but theres not too much running aroudn in these forums about 120VAC electronics.
That is because playing with mains when you don't know what you are doing is dangerous and can be fatal. I am surprised a teacher has given you this to do with so little knowledge of electricity. I would first check that your teacher is fully insured for when your parents try and sue over your death.
I would use a SSR solid state relay and turn it on and off at regular intervals to control the power. Get a relay that is rated at a current at least twice that you need to switch. The ratio of the on time to the off time determines the power. The code looks exactly the same as the code to flash an LED.