With any game, I try to find content from the best players and the best coaches – not just content that’s popular or entertaining. Here are some good places I’ve found:
https://www.reddit.com/r/LoRCompetitive/ is a small community with guides and educational content. This is the current tournament meta. (as of sept 2020).
For the Ranked ladder: NicMakesPlays has a Twitch stream. He’s reached #1 Masters and is often in the top 10.
- Masters of Runeterra – only Masters players post; though everyone is free to view
- and there are coaches with discords like AnnieDesu and CastMinTv