You will likely want to check the official information from time to time. Here's the list for all their social media!
Playlist to their music.
Curious to know if your device can handle the game? And other Frequently Asked Questions? Be sure to check the FAQ on reddit and also the one on the official website about PC version about the game.
Want to know more about the story? Genshin Impact made a manga that's posted on their official website! There's plenty of chapters and they're all available for free to read online.
Here is a very useful feature that was made on reddit. This interactive map helps you find the interactables in the world. Some may be hidden when you play the game, so using this can really help find the stuff that you need.
Puzzles, Secrets, and Hidden Chests in Liyue
ATK% VS Physical/Elemental DMG% in Genshin
Puzzles, Secrets, and Hidden Chests in Dragonspine
Mondstadt Side Quests
How to make & link your MiHoYo account
Tartaglia "Childe" Boss Fight Guide