2-2-2 drill is quite a bit easier than swimming regular butterfly. Push off the wall and take two regular butterfly strokes, then two strokes with one arm, and then two strokes with the other arm. The arm that is unused stays out front, not at the side. Resist the urge to make those two one-arm strokes feel like one-arm freestyle. Keep the dolphin motion going with the rest of your body even with that one arm leading long in front of you. It’s normal to roll a bit onto the side of the arm you are using. If you breathe while taking a one-arm stroke your head will be tilted to the side as well – it’s very hard to lift your head straight up when doing the one arm strokes.