Telemachus is the son of Odysseus and Penelope. He is a young man at the beginning of The Odyssey. Telemachus is trying to fill the role of his father as leader of the household. He dismisses the suitors who seek his mother's hand in marriage. When Penelope is upset by the song about the sufferings of the Greeks, Telemachus is not sympathetic. He tells her that Odysseus is not the only one who is gone and that she should go to her room. This is an example of Telemachus assuming a fatherly or husband-like position of power. Telemachus is willing to journey to find news of his father, he does not show signs of fear, he has a sense of duty, which is encouraged by Athena.
It is important to hear Telemachus' story first, because it sets up all of the information about Odysseus. It let's the reader know what has happened to the family before the story begins. Also, Telemachus' journey to find his father, mirrors Odysseus' journey home. Both men are journeying and growing simultaneously.