Trojan War

The sacrifice of Iphigeneia whom King Agamemnon offered to her for the passage of the Greek fleet to Troy; for this Artemis stood against the Greeks, she was beaten by Hera in an angry contest of the gods.

Greek.

When Menelaus and Helen married, every other man had to swear an oath saying they would not bother the relationship (as Helen was the most beautiful women in the world). However, when visiting Sparta, Helen was kidnapped and brought to Troy. So, Menelaus rallied the Greeks and set out for Troy. In a sense, Menelaus made the decision to go to war with Troy.

he died...

it started when Paris kidnapped Helen when Aphrodite sent a lying message to Menelaus that his brother, Agamemnon needs him ,but in some version, Helen fell in love with Paris that's why they eloped and went to Troy.

The Trojans gave a hallow wooden horse filled with soldiers the Greeks as a "Gift", but in the night the soldiers came out of the horse and successfully seized the city.

Traditionally, the Trojan War was fought between 1194 and 1184 BC. But, of course, there is no actual timing indicated in the histories. Historians date it based on references made in writings about the war and what is known historically about its almost mythic participants.

There wasn't much record keeping done during the Bronze Age, even by the Greeks.

The war was fought entirely on the shores of Troy, which was a major city in Asia Minor (modern Turkey).

During the Trojan war the Greeks gave a Trojan horse to the Trojans as a gift. In fact, the horse was filled with soldiers. At night the soldiers in the horse jumped out and opened the Trojan gates. Afterwards the other Greek soldiers climbed into the gates. That was the story of the Trojan war.

There was a beauty contest between Hera, Athena, and Aphrodite and Aphrodite won. She promised Paris, the prince of Troy, the most beautiful woman in the world, named Helen, to be his wife. There was one problem, Helen was married. The other goddesses were enraged by Paris' abduction of Helen and this caused the Trojan War.

Upon Agamemnon's return from Troy he was murdered by Aegisthus, the lover of his wife Clytemnestra.

The city of Troy was in Greece, so the Trojans would be Greek.

Hercules

the mycenaens

Apollo

The son of Aphrodite, Aeneas, was told by his mother to flee after Troy was destroyed and he became one of the first great heroes of Rome.

In the story of the apple of discord its Aphrodite that makes Helen fall in love with Pairs so Paris gives her the apple

From Wikipedia:

At the fall of Troy, [Cassandra] sought shelter in the temple of Athena, where she was violently abducted and raped by Ajax the Lesser. Cassandra was then taken as a concubine by King Agamemnon of Mycenae. Unbeknownst to Agamemnon, while he was away at war, his wife, Clytemnestra, had begun an affair with Aegisthus. Clytemnestra and Aegisthus then murdered both Agamemnon and Cassandra. Some sources mention that Cassandra and Agamemnon had twin boys, Teledamus and Pelops, both of whom were killed by Aegisthus.

She built the big hollow horse they used to trick Troy.

Yes. She was on the side of the Trojans.

There was no Sirion in the Trojan War.

the greeks and the trojans

Hector was King Priam's eldest son, and was the commander in chief of the Trojan forces. Hector was the best warrior on the Trojan side.

Helen wasn't on a side she was the one they were fighting over. So she was on both sides i guess. I don't know: read the Trojan War.