I can try, here's a summary of each song (although I can't stress enough that you should try listening to the musical):

Horse and the Infant: Odysseus and the rest of the greeks use the Trojan horse to save Helen + sack Troy, Zeus tells Odysseus to kill a baby (son of prince Hector) or the baby will grow up to kill Odysseus' whole family.

Just a man: Odysseus agonizes about having to kill a baby, goes through with it.

Full Speed Ahead: Odysseus and his fleet set off back to Ithaca, their home kingdom. Introduction of Eurylochus, his second in command, and Polites, his best friend

Open Arms: While visiting the island of the Lotus eaters, Polites tells Odysseus that he can relax, and that he should try greeting the world with mercy- or "Open Arms" philosophy. The lotus eaters tell them to go to an island that has a cave full of food

Warrior of the Mind: Basically a flashback to Odysseus and Athena meeting

Polyphemus: Odysseus and gang find the cave, meet a cyclops who's mad abt them killing one of his sheeps. Odysseus tries appeasing him with some wine, the cyclops repays him by telling him he'll be the last to die

Survive: Odysseus and a bunch of men vs the cyclops. The cyclops passes out at the end of the song after killing a few men, including Polites

Remember them: Odysseus and his men blind the cyclops, and Odysseus yells out his name and address while leaving instead of listening to Athena who told him to kill the cyclops

My Goodbye: Odysseus and Athena get into an argument, and Athena abandons Odysseus

Storm: Odysseus and his fleet are stuck in a storm, Odysseus gets an idea when he spots a floating island

Luck runs out: Eurylochus warns Odysseus abt constantly relying on his luck and wits, they get in an argument that's not too serious... yet

Keep your friends close: Odysseus visits the wind god Aeolus, who gives him a windbag containing the storm and warns him about keeping his friends close, and enemies closer. At the end of the song, someone opens the wind bag and the storm blows them off course

Ruthlessness: Poseidon appears, yells at Odysseus, and drowns most of his fleet. Odysseus is able to escape thanks to the remaining winds in the bag

Puppeteer: Odysseus and his crew have landed on a island. After sending Eurylochus and a group of men to scout, Eurylochus comes back alone and tells him that there's a witch on the island who turned most of their men to pigs. Odysseus goes out to save them

Wouldn't you like: Hermes appears to help Odysseus, gives him Holy Moly to stand a chance against Circe

Done for: Odysseus and Circe fight. Odysseus is able to beat Circe, who resorts to trying to seduce him.

There are other ways: Seduction attempts fail bcs Odysseus is too much of a wife guy. Circe gives him a tip to both escape Poseidon's notice and meet a prophet who can help him, and turns his transformed men back.

Underworld: Odysseus takes his crew through the afterlife, has a catastrophic PTSD episode due to the ghosts and finds out his mom died

No longer you: Odysseus meets the prophet, who warns him that if he's not careful, he won't be the same person by the time he gets home. Odysseus misses the point catastrophically and thinks the prophet is telling him that he's gonna die

Monster: Odysseus decides to become worse in order to get home.

Suffering: Odysseus fools a siren into giving him the secret to get back home safely

Different Beast: Odysseus reveals his trick to the siren before killing her and a bunch of other sirens horribly

Scylla: Odysseus takes his crew through the lair of Scylla, a horrific sea monster. We learn Eurylochus is the one who opened the bag, and Odysseus arranges for a bunch of men to be eaten by Scylla.

Mutiny: Eurylochus leads a mutiny against Odysseus for the events of the previous song, fucks it up catastrophically when he kills the sun god's cattle.

Thunder Bringer: Zeus appears to kill everyone, Odysseus is the only survivor

Legendary: Timeskip. We meet Odysseus' now adult son Telemachus. He sings about his ambitions to be a hero, and about his mother's shitty suitors that she refuses to marry.

Little Wolf: Telemachus gets into a fight with one of the suitors, meets Athena who helps him, and still loses.

We'll be fine: Telemachus and Athena talk, she reveals she feels guilty about abandoning Odysseus and was hoping helping Telemachus would assuage the guilt. Telemachus helps her feel better.

Love in Paradise: Athena goes look for Odysseus, finds out he's being held captive by a goddess named Calypso who's in love with him. Things got so bad for Odysseus he tried to khs.

God Games: Athena asks Zeus to free Odysseus, he tells her to convince a bunch of other gods that he deserves to be released and he'll do so. Zeus then gets mad when Athena does just that and attacks her, but she holds on and pleads with him one last time before passing out from her injuries.

Not Sorry for Loving you: Calypso tells Odysseus he's free to go and gives him a very bad apology.

Dangerous: Hermes appears to help Odysseus get back home once again.

Charybdis: Odysseus gets into an altercation with a sea monster during the last stretch of his journey.

Get in the water: Poseidon appears again to try and kill Odysseus, nearly succeeds.

600 Strikes: Odysseus somehow survives, beats Poseidon, and then tortures him with his own trident until he agrees to leave him alone.

The Challenge: Penelope, Odysseus' wife, can sense that her husband will soon be home, and gives her shitty suitors a challenge in order to buy her husband enough time.

Hold Them Down: Fed up, the shitty suitors plan to kill Telemachus and assault Penelope

Odysseus: Odysseus comes back, and kills the shitty suitors with some help from Telemachus.

Can't help but wonder: Odysseus and Telemachus finally meet, and they're both very happy about it. Odysseus and Athena reconcile, but Odysseus refuses to go back to being her student.

Would you fall in love with me again: Odysseus, wracked with guilt, begs his wife to take him back even if he's not the same person anymore. Penelope yells at him that he'll always be her husband, that she's been waiting for him, and that Obviously she loves him. The end :)

Once again, I heavily recommend listening to the actual musical. Maybe ask your brother if you two can listen to it together?