Healing in Wrath is relatively easy compared to other expansions.
Holy Paladin is a great choice and a highly sought-after healing spec in raids. Just make sure to keep Beacon of Light on the tank, maintain Judgement of the Pure buff and spam Holy Light - everything else you’ll pick up with experience.
As for Resto Druid, there's not much to micromanage at all, though I understand that healing can feel complicated at first - it happened to me too. Just spam Wild Growth, and while it's on cooldown, spam Rejuvenation. If you get an Omen of Clarity proc, use Lifebloom to regain mana. If someone is in danger, use Swiftmend. There are a couple of other mechanics, but you'll learn them with time.
Resto Druid is super fun, though!