Ironically, the most lore-accurate part of the entire thing is the narrated few minutes of the First Age that's shown in the prologue, which they have no rights to beyond the brief references made to it in the LoTR appendices. They actually did a reasonably good job with bringing that to life while making sure to stay within the constraints of the very limited material they had to work with. There are also a bunch of brief First Age references and easter eggs scattered about the season.
Now, let's move on to the Second Age. Off the top of my head, here is everything in all 9+ hours of the show so far that was actually pulled from the books:
Some of the characters and locations that exist in the books...exist in the show.
They briefly set up the faithful versus the King's men situation in Numenor.
Tar-Palantir dies.
Sauron is in disguise and helps guide the Elven smiths, although the manner and timeframe in which this occurs is vastly different from the books.
The three elven rings are forged in Eregion by Celebrimbor (but seemingly none of the others have been made at all yet).
We're up to maybe 30 minutes of screen time now. Then there's the other ~8-1/2 hours of Galadriel wandering the world with her buddy Sauron, Mithril as magical Silmaril dust, the Elves suddenly dying because...reasons, Elves and Numenoreans battling orcs in proto-Mordor, Harfoots and not-Gandalf fighting non-binary Slim Shady wizard, magical volcano sword-key, Durin vs Durin, sailboat sabotage gone awry, Isildur "dying", Celeborn going AWOL for hundreds of years, etc. So yeah, just a few adaptorial liberties taken. No problems here.