If you want some cool free wings, link your PSN to battle.net to receive the Mercy Wings. Also, you can farm Gardens of Hope Tier 1 for the “Mysterious Chest” (looks like normal white chest but named as such) for the Falcon Wings.
With more time investment, you can get the green angel wings and the green demon wings by doing all class-set dungeon achievements on regular and master difficulty, respectively.
There’s also a dude selling cosmetics for 25fg a pop iirc.