As a new healer I’d focus on basic concepts of healing and learning your role.
Which spec you do it on is largely irrelevant, disc may actually be easier as it is semi-similar to a dps caster and you have less healing spells to manage/know when to use or not.
If you’re having trouble understanding when to heal and which spells to use in which situation, playing something like Resto Druid or Holy Priest will be more confusing, as they have many more healing spells.
Others have mentioned mouseover macros, and things like healbot/vuhdo. I personally use Clique and mouseovers. So, I don’t have any healing spells on my bars, they’re tied to mouse button clicks with Clique. And because Disc has fewer healing spells, this works wonderfully. My action bars on disc are less populated than any other healer spec I’ve set up. I’d highly recommend getting something like Clique as it gives you a huge amount of bar space and mechanical efficiency.
Anyway, concepts like triage, learning and responding to damage patterns, getting a feel for how long you can rely on atonement healing (healing thru doing damage) and when you need to shift into direct healing, making sure your unitframes are the correct size and in a good place for you so you don’t misclick, are all universal healing concepts. Best to learn these now and not necessarily focus on the spec so much. If you tie your practice, knowledge and ability to heal completely to the mechanics of a single spec (or switch in order to do something “easier”) that’s the equivalent of treating the symptoms and not the cause, I guess is what I’m getting at.
All healers do the same basic things: set up for a pull, do dps for as long as possible, heal the incoming damage from mobs/enemy players.
How each spec does these things are where it gets really fun and interesting, but is a little more in depth than I’d worry about right now. As long as there is no complete party wipe, you’ve succeeded.
If you have any questions, I’d be happy to stream some simple gameplay for you, discuss UI options, addons, healing concepts, etc, you can add my discord at distance#4423.
P.S. in an epic bg this is slightly different. There’s so many players, people are spread out, oftentimes running off to do their own thing, it’s very chaotic and you’re not meant to handle it all by yourself and be responsible for everyone’s health lol. Get a good unit frame addon that shows you clearly who is available to heal, stick with a group that knows what they’re doing and keep them alive. xD