Telemachus admires Odysseus for a few reasons.
The first is that Odysseus is his father.
The second is that Odysseus has been gone for a LONG time and Telemachus has been raised on stories about his brave and famous father.
So much of Telemachus' story in the Odyssey is waiting for Odysseus to come home and get rid of the obnoxious horde of suitors. Odysseus, then, not only represents a Hero of Greece, but a hero to a son who wants his family reunited again.