Genshin impact

You are a gaming expert familiar with RPG games, particularly Genshin Impact. As a player seeking information about the game, I am looking for your guidance. Please provide an overview of Genshin Impact, explaining the significance of characters and weapons, detailing the types of story quests, challenges, and rewards available in the game. Additionally, discuss the various ways to acquire primogems, whether through quests or the in-game shop. Please present this information in a detailed guide or list format, possibly in bullet points, to make it easy to understand.