What are the elements of storytelling and fiction in Things Fall Apart?
I'm not certain in which context you mean "elements"; pertaining to history or to literary devices. So I'll give you a little of each and point to an additional source.
Things Fall Apart, by Chinua Achebe, was written in 1958, at the commencement of Nigerian Independence, but it tells the story of pre-colonial village life of the 1890s. In this regard, it could be said that Things Fall Apart is purely fiction. However, Achebe used preserved oral story traditions, proverbs, myths and folk tales to reconstruct an authentic picture of pre-colonial Nigerian life.
The Igbo tribes, several hundred of them, have been in about the same location as they are today in Nigeria for between 2,000 and 3,000 years. They are an ancient people who have left behind artifacts of pottery and forged metals. The Igbo legends tell that the Igbo believe in one supreme god, called Chukwu, who demanded obedience. When European missionaries and colonialists came to Igboland, there was a clash of ways and beliefs resulting from European ideology of conversion and subjugation (it escaped these Europeans that the notions of "conversion" to Christianity and "subjugation" are contradictory being antithetical).
The tone of Things Fall Apart (the narrator's tone of voice reflecting feeling toward the story and/or characters based on language alone) is that of an ironic storyteller. The mood (the feeling of the story derived from the setting, objects, language, details) is energetic and energetic with a touch of desperation, and it vacillates between the balanced village calm and Okonkwo's grasping, bad temper and illogical behavior. The point of view is third person omniscient that provides the thoughts, feelings, actions, motives of any character, not just the protagonist, Okonkwo. The main themes are balance and imbalance between the male and female energies of Earth and the balance and imbalance between clashing cultures (i.e., the Igbo peoples against European intruders).
For additional information on the historic elements of Things Fall Apart, see the Preface, Forward, Introduction and Notes in the Heinemann Educational Publishers, of Harcourt Education Limited, 2000 edition of Things Fall Apart