Begin your first chapter by branching out from the initial paragraph along several different paths. Create several drafts of your first page to determine which path complements your vision for the entire book. For example, a science fiction novelist writing about a distant galaxy can try out opening pages describing a planet, detailing an alien conversation or profiling a lonely starship captain.
Reveal information about your protagonist and his purpose in the story as you write your first chapter. You can opt for a chapter-ending reveal of the character's name or use a conversation between the protagonist and another character to detail his background.
Use your first chapter as an opportunity to set the place, time and emotional state of your novel. The first chapter of a World War II-era romance story differs greatly from the first chapter of a modern-day crime drama. Allow characters to reveal small details like the temperature, the hour and familiar landmarks to keep your first chapter from sounding like a travelogue.
Unveil the back story to your novel by using flashbacks and narrative reminiscences in the first chapter. For example, a novel about treasure hunting can start with pirates burying their loot on an island two centuries earlier. Keep these flashbacks relatively limited in detail to build suspense in proceeding chapters.
Employ the same tense and terminology in your first chapter as you plan on using in following chapters. Your readers will be confused if you flip from a third-person to a first-person narrative without explanation. While imaginary words in science fiction and fantasy can be left untouched in the first chapter, the writer should reference these terms later to tie up loose ends.