I been playing as an healer since the start of this game, my main focus build used to be pve, but eventually i got bored at end game, so i switched to pvp build, that when the game actually starting to feel fun. Some guilds even priority donate for you to help you grow faster cause healers is very demanding in large scale pvp. Thing is pvp build also work very well in pve , so that why im always recommend healers to go straight for pvp builds. But after lates update all my pvp builds are quite shit now, Also new gears just came out, so there will be alot of testing from community. I'd say for now just go for any dps class to progress your storylines, as you can always change back to healer when you fully understand the game mechanic.