Beginner Character for OW?

Many of my friends claim that Mercy is one of the easiest to learn characters. You can easily avoid enemy combat and usually in casual at your MMR people will be too busy hitting the guys you are healing. This is a personal opinion but I really believe mastering Mercy goes a long way, although, again, many claim otherwise. You can reach Master if you only play Mercy - some people even tilt at the sight of such players.