You are going to receive a brief summary given the lack of space that I have to write a response and the fact that you have asked for a summary of two chapters. Please refer to the enotes links I have provided below to gain more information about the chapters you have asked about.
Chapter One introduces us to Okonkwo, the protagonist of the novel, who is described to be an amazing man because of his wrestling prowess. He is now a wealthy farmer with three wives and lots of children and is also famed for his bravery in war. Okonkwo, because of his position in the village, is chosen to adopt Ikemefuna, given to Umuofia by the village of Mbaino to stop war. One of the reasons Okonkwo works so hard is that he has done his best to escape the influence of his father, who was lazy and neglected his wife and children. Unoka, his father, also was in debt to lots of people and never repaid those debts. Okonkwo is ashamed of his father and does everything he can to be as manly as possible. The chapter ends with a story about Unoka and the debts that he had accrued.
As Chapter Two opens, a kind of tribal gong sounds through the night in Umuofia. We are told that Umuofia is a community consisting of nine Igbo villages that are closely linked. All the men are summoned to the central marketplace and they are told that the wife of Ogbuefi Udo has been killed in Mbaino and the people of this rival village are to receive an ultimatum: they must choose war or offer a young man and a virgin to Umuofia as a kind of compensation. Okonkwo goes to Mbaino as the emissary of war and returns with a young girl and Ikemefuna, a fifteen-year old boy. The elders of Umuofia say that the girl should replace the dead wife, and place Ikemefuna in Okonkwo's care.
Okonkwo is shown to be a very hard worker who does not feel tired. He is very dictatorial as regards the rule of his household. He expects the same strength from his wives and children, and they suffer as a result. In particular, Okonkwo beats and chastises his son, Nwoye, because he thinks Nwoye is being lazy. Nwoye as a result is growing up to be unhappy.