two leds with one pin ie. when pin high ledA on, when pin low ledB on?

Using Arduino General Electronics
3

I want to control a red and green led with one pin. When the pin is high I would like to light a red led and when its low I would like to light a green led.

Easy. Use a NOT gate, like 74LS04 or any 74XX04 or 4049 or 74XX00 <-- NAND gate.