which aspect of life the second deity is associated with?
Water and creation.
Enki
Enki (; Sumerian: ) is the Sumerian god of water, knowledge ("gestú"), mischief, crafts ("gašam"), and creation ("nudimmud"), and one of the Anunnaki. 
how is venus depicted in culture? In Sumerian religion, Inanna was associated with the planet Venus. in which areas was this religion practiced? Sumer, first literate civilization of ancient Mesopotamia. what are the origins of this religion's name? UNANSWERABLE what were their major religious deities? Enil, Enki, etc.
wiki:7676260
Enki [SEP] Introduction
Enki (; Sumerian: ) is the Sumerian god of water, knowledge ("gestú"), mischief, crafts ("gašam"), and creation ("nudimmud"), and one of the Anunnaki. He was later known as Ea in Akkadian and Babylonian mythology. He was originally patron god of the city of Eridu, but later the influence of his cult spread throughout Mesopotamia and to the Canaanites, Hittites and Hurrians. He was associated with the southern band of constellations called "stars of Ea", but also with the constellation AŠ-IKU, "the Field" (Square of Pegasus). Beginning around the second millennium BCE, he was sometimes referred to in writing by the numeric ideogram for "40", occasionally referred to as his "sacred number".