Writing the First Five Pages

Adventures in YA & Children's Publishing is hosting a First Five Pages Workshop, where you can read the first five pages of someone's manuscript and offer them helpful suggestions for revision. They also share some good points to keep in mind when writing/reading the first five pages of a novel, such as:

"Are there enough grounding details to make the story feel real and alive? Is there enough introspection and connection to the main character? Too much? Is there enough dialogue? Too much?"

Those first five pages can be tough to write, so make sure to check out the full list.

Once in my writers group, someone mentioned that the first chapter of a novel teaches the reader how to approach the rest. What are you "teaching" your reader in those first five pages? Ideally, it should be similar in tone to the rest of the novel and touch on major characters/settings.

What are your tips for the first five pages?