I have been playing wow for 2 weeks now .just got my first character to lvl 80 . I have just started playing pvp today and i was looking for tips so that i can improve as i play more .
I will mostly be playing healer classes and for the time being play this holy priest before branching out to other healers .
Ty all in advance for giving any tips or guidance 
Stick to bg blitz ranked mode for a while untill you are confident about your skills then step into the arena.
Currently Holy priest have hard times 
, but few tips from casual pvper.
To faster gear up, do weekly sparks and other pvp quests. For sparks just find group in group finder. At begining do not try to do DPS, most important thing is to learn how to survive. Learn positioning, basically how to hide behind pillars etc… Try to track at begining enemy CC spells, like cyclone, hex, polymorph and avoid with Lining, fade or swd.
Good luck fellow holy priest!
Meet like minded players in BGs, Arenas and guilds and set personal goals in whichever bracket you or you guys want to focus on and have fun 
Watch skilled players on youtube, Hydra for example used to be the best Priest in the world, if not the best player in the world.
His main account was rank 1, highest rated and his other account was rank 2, second highest rated on the arena ladder.
I’m not sure what happened to him but I think he still plays.
You should watch good players when you’re on a break and then when you’re playing just put on your favorite music genre and farm battlegrounds and arena, there’s no better way of learning than to have fun and PVP in Wow is very fun when you start to get the hang of things.
You might need a couple of PVP addons for arena but the good thing is, you don’t need many addons for PVP at all.
Later down your path you should google focus macros, they are very very useful, so useful that they will actually increase your winrate.
Good luck !!
Get addons to help you out, they are invalueable