It all started in Ithaca, Where Odysseus is born and raised, he then joined the army and attacked Troy, when they arrived they lost horribly, but Odysseus had an idea, and this idea was called the "Trojan Horse" which worked wondrously.
After the battle Odysseus and his men head back home but get lost at sea, and on his way back he encountered many problems, one of which was the lotus eaters, where Odysseus tells his men not to eat the lotus flowers, because whenever you eat the lotus flowers you actually lose time!
The next obstacle they encounter is the Isle of Polyphemus, that has a cyclops living on it called Polyphemus, they blinded the Polyphemus with a stake because they needed to escape but, Polyphemus then told his father Poseidon that Odysseus and his men blinded him, Poseidon then cursed Odysseus and his to not return after many years.
After blinding Polyphemus they then met Aeolus the ruler of the winds, when they were on their way Aeolus then gave Odysseus a bag containing all the winds except the west wind which would've made it much easier to head home, but the crew of Odysseus were curious and opened the bag which let all the winds out and they were once again trying to get home.
Soon after they left Aeolus, Odysseus entire fleet soon sunk all but Odysseus ship, they then landed on island which had a witch named Circe, she turned all his men into pigs except Odysseus, because she had a liking in him, so they agreed that after a year Odysseus was supposed to love Circe, a year later Circe and his men headed back to his home.
The Island of the laestrygonians was the next island that they arrived at and there they had to fight giants, which they won.
He then enter Hell (Underworld) to find out how to exactly how to get home. There was a person who was down in the Underworld, that was killed in Troy so Odysseus goes to the Underworld to talk to this person but this man was actually on the Trojan side instead of the Greeks.
Odysseus and his crew then passed the island of the Siren's, Odysseus ordered his men to put ear wax in their ear and tie him to a pole, this is because the sirens sing beautifully bu whenever you hear them sing and they try to land on the island, their is a lot of jagged rock which would sink them on once they swim to shore the siren's would eat you, and so the reasons Odysseus ordered his men to tie him to a pole it was so he could be the only one that heard the sirens sing and live to tell about it.
He then got close Scylla, because they did not want to sink, but the gods told him that if you get close to Scylla six of his men would be taken and six men were taken, he still went through because he needed to get home.
They then got close to the isle of Helios, his men were hungry and they got on the island and all of the cattle on the island are under the protection of Helios , so when they arrived they eventually killed a cow, which got Helios mad and then Zeus sends a lighting bolt to Odysseus ship, and destroys his ship, and everyone dies except Odysseus, who was hanging of a tree branch.
He was then washed ashore to an island Ogygia where he was supposed to be Calypso lover and he was there for many years then he was ordered to be let go by Zeus.
After 2 decades he returns home, and when he returns he finds that peopel have been trying to marry his wife to become king, but that is an extra part of the story which would take to long to explain.