If the first line sets the tone, the first page(s) lay the groundwork for the entire tapestry of a book. What does the reader expect: genre, point of view, place (time and geography). How about mood?
If the compelling first line did its work the reader is interested. Now you have to round out the experience. Did the first sentence make them uncomfortable? Or pose a question. I’m again reminded of Celeste Ng’s “Lydia is dead. But they don’t know this yet.” The opening to Everything I Never Told You.
The first pages need to immerse the reader in the story, and most likely in a significant, if not main character. What kind of protagonist is at the heart of the tale?
What about the first pages of a “next in series?” The first pages must bring fans back to a familiar world while introducing it to new readers for the first time. This brings the complication of repeating information in a new way. Reassuring fans that they will enjoy this installation as much as they did the last.
For ongoing discussion and examination of this topic look to the weekly First Two Pages blog hosted by Art Taylor athttps://www.arttaylorwriter.com/blog