I’ll give you a start but you can do a little research so that next time you can better know your subject matter.
Tammuz, ancient nature deity worshiped in Babylonia. A god of agriculture and flocks, he personified the creative powers of spring. He was loved by the fertility goddess Ishtar, who, according to one legend, was so grief-stricken at his death that she contrived to enter the underworld to get him back. According to another legend, she killed him and later restored him to life. These legends and his festival, commemorating the yearly death and rebirth of vegetation, corresponded to the festivals of the Phoenician and Greek Adonis and of the Phrygian Attis. The Sumerian name of Tammuz was Dumuzi. In the Bible his disappearance is mourned by the women of Jerusalem (Ezek. 8.14).
The setting of different dates for Easter from year to year is explained thus, in Schaff-Herzog Encyclopedia of Religious Knowledge, Vol. 2, page 682: “The present variable time was appointed by early Romanism in amalgamation with the very ancient pagan spring festival to the goddess of spring. It was fixed on the Sunday immediately following the 14th day of the paschal moon which happened on or first after the vernal equinox.” Please note Col. 2:16, “Let no man judge you in meat or in drink, or in respect of an holy day, or of the new moon, or of the Sabbath.”
The Babylonian “queen of heaven,” Semeramis, the wife of Nimrod, was the original impersonation of the heathen goddesses, Astarte and Venus of the Greeks, Juno, of the Latins, Ashtoreth, of the Zidonians, Ishtar of the Babylonians, and Eostre, the goddess of spring, of the early Anglo-Saxons.
Semeramis was the wife of Nimrod who was the great grandson of Noah so you can see when it really started.
Oh, and while we're at it, Astarte was not Greek at all she was Phoenician. And Venus was not Greek, she was Roman, like Juno. So which exactly was the Roman "Queen of Heaven"--Venus, or Juno? The Greek equivalents would be Aphrodite and Hera. Seems your source is a bit confused.
This fetish of tracing every pagan deity to Babylon is nonsense, and there isn't a shred of historical evidence to support it. Roman paganism grew up in Italy as a complex mix of Indo-European (Latins, Oscans, Umbrians) and other elements (Etruscans). They had their own pagan traditions and certainly did not need any help from the Babylonians to populate their pantheon.
And when the Romans later borrowed gods/goddesses, they tended to borrow their names as well. So Persian Mithras becomes Roman Mithras. Egyptian Isis becomes Roman Isis. That the names of Venus and Juno are very distinct from Semiramis ought to be a clue that it was not a borrowing.