IMO Archon would be easier for an inexperienced holy priest to excel at, then work your way over to Oracle for more buttons to press.
With Archon and halo rolling, dish out your holy words liberally and flash heal and/or prayer of healing (if you go that route) for filler, using empowered renew/pom on cooldown.
The way you play will also depend on if you go the lightweaver route or answered prayers. If you go lightweaver, you take all of the talents that increase the length of apotheosis and help prayer of healing. If you go the answered prayers route, you’ll be using a lot more pom, so you make sure you’re belting them out when available and take the talent that turns divine hymn into a pom spitter. Both ways maximize the uptime of apotheosis. Using answered prayers, you’ll cast prayer of healing less often and only under prayer circle or with the talent that gives you 3 instant pohs from activating apotheosis. Archon will also give you a lot of surge of light procs while halo is rolling.
Ease into holy with archon and when you want more complexity, go Oracle.
Don’t worry about the shamans, they chain heal their way to victory quite easily. 
Parses mean nothing if the boss keels over, you did your job. 
Here is a link to my logs. Keep in mind, I’ve been playing Oracle for a few weeks now and my higher parses are from pugs usually.
~https://www.warcraftlogs.com/character/id/73267752?difficulty=4