The gods have been around since old earth. Before the system apocalypse they only rarely intervened on earth as the magical power of the world was low the pantheons got distracted by other realms. Leaving earth mostly under the purview of the god known amongst most human cultures as the creator, the main patron deity of humans. Known over the ages by many names it's unknown if this god is male or female. From books and records found from that time some of the names were, mother earth, Eru, Allah, Jahwe, and The One. These days people just call her the earth-mother as its preferred form when showing itself to mortals is that of a grandmotherly old lady.
After the system apocalypse, the pantheons slowly gained strength with the new influx in magic. And when the 2nd age happened and all the planes were merged the pantheons greatly grew in strength. Members of each pantheon were often named very differently on different worlds and by different races. But after a few ages of intermingling, most use the name in the basic common language for the god when amongst mixed races.
Even though each race has its own patron deity by now with the intermixing and intermingling of races and cultures whichever deity you do or do not pay homage to doesn't really matter.
Most of the gods have races they have created in their image with pantheons often having a common theme. A few examples being the old earth Egyptian pantheon being responsible for most of the beastkin races. Like Bastet being the patron of catkin. And Anubis being the patron of gnolls.
If you spot this tale on Amazon, know that it has been stolen. Report the violation.
The main races and patron deities are:
Dwarf - Erda or the stone-mother thought to be the sister of the earth-mother
Elves - Aina who is also the mother of Titania, the patron of the fairies.
Halflings - Loki the trickster god
Minotaurs - Minos
Kobolds and dragons - Fafnir, father of dragons. The dragons actually created the kobolds as a slave race, but Fafnir himself stepped in to free them and took them under his wing.
Werewolves - Odin, the storm lord. Married to Freya the goddess of maidens, motherhood, and women in general.
A lot of professions also have patron gods although these are more commonly used by their cultural names.
God of blacksmiths - Hephaestus, Weyland, or Ymir. Married to Erda
Agriculture - Radegast, Demeter, Osiris. As it shows up in both male or female form depending on the culture, unknown if it's one god or multiple working together.
The lists of Patron deities and their names can go on and on.
After the planes or planets were merged in the 2nd age the amount of work the gods had to do increased so they started to elevate mortals who had done great deeds to godhood and demi-god status, Primus is one of those beings.
After some disastrous occurrences in the past, the gods rarely intervene directly, working through giving quests to favored mortals or giving small amounts of power to those with a divine class like priests and clerics, often limited in giving powers related to their disposition. Like clerics of Odin being able to wield lightning as a weapon but almost no control over the other elements. While a cleric of Hephaestus would excel at using fire and utilizing metal.