Here's a sort of checklist I made a long time ago for what chapter one needs to do.
Introduce the protagonist. This includes:
Status: their role in society; profession, approximate age, etc.
Personality: perhaps the most important part.
Relationships: some relatives, friends, acquaintances, rivals, and/or enemies.
Introduce the setting. If it's the real world all you need to do for this is make that clear. If not, you must introduce the world:
Physically: Is it basically set on Earth, just not the real Earth? There are other options (besides sci-fi mulitplanet settings where each planet is basically Earth-like). One I created was a flat water world with a few massive pillars of land that people live on (travel between them required powerful magic).
Culturally: Do the people have significant difference in values from those in this world, or any exotic customs? Religion? Government?
Its rules: Reveal the technology level, and any magic system, as early as possible so we know what is and isn't possible in this world. Although some of this responsibility can be delegated to chapter 2 or maybe even 3, you should start in chapter 1. Also, if the POV character doesn't know how the magic works, then of course the audience doesn't need to know yet.
Introduce the plot. It doesn't have to start it directly, but it should at least include a "hook" that shows how it's going to get started.