Short answers, pulled from the story.
The year 753 BC marks the traditional founding of Rome. According to legend, Romulus and Remus were born to Rhea Silvia, a Vestal virgin impregnated by Mars, survived exposure in the Tiber River, and were suckled by a she-wolf before being raised by a shepherd.
Numa Pompilius, the Sabine second king, established most religious institutions including the Roman calendar and priesthoods like the Salii and flamines. His reign closed the doors of the Temple of Janus, symbolizing peace, though they remained open until Augustus reopened them centuries later.
Deities of the upper heavens received white, infertile victims like Juno's white heifer or Jupiter's castrated ox. Chthonic gods such as Dis pater received dark, fertile victims during nighttime rituals that took the form of holocausts or burnt sacrifices without shared banquets since living beings cannot eat with the dead.
Vestal Virgins formed Rome's most famous priesthood consisting of six women devoted to Vesta's sacred hearth. Unlike male priests, Vestals took vows of chastity strictly enforced; pollution resulted in burial alive.
Polytheism ended with adoption of Christianity as official state religion in 380 CE. His successor Theodosius I extinguished Vesta's sacred fire and vacated her temple after Christian emperor Gratian refused pontifex maximus office.