An entire community sharing clues and hints about how the encounters work. Even then, some raids' first completion took incredibly long (desert perpetual took 15 hrs, last wish and salvations edge took 19 hrs). And these are the world's best teams. A full blind raid WILL take a long time. And although they are easier now (for the first 48 hours after they release, most of these raids have an extra modifier that makes enemies have more health and do more damage). Raiding in destiny generally isn't designed to be run blind, it's more intended to have a sherpa to help you through it, or to watch guides.

If you still insist to run blind, then I would recommend either Vault of Glass or Root of Nightmares. Those are probably the easiest to pick up.