Who created the first generation of human in Greek mythology?

There actually is no correct answer to your question, because there is more than one cosmogony among the ancient Greeks. Scholars believe that the variations arise from the re-telling of the origin myths of the earliest Indo-European and Indo-Iranian tribes. Further complicating the issue is that these creation myths probably had a profound influence on middle eastern myths, which, to a much lesser extent, influenced them.

The earliest surviving version of Greek cosmogony (cosmogony means the origin of the cosmos, which formed out of chaos) is the Theogony of Hesiod. This was written in classical, Homeric Greek between 2700 and 2800 years ago. It assumes a formless and disorganized set of matter and energy with "heaven" above chaos below that and Tartarus below that. These realms were thought to be primordial powers as well as places. Uranus was the first and greatest of the Titans, and was identified with heaven. Gaia was identified with chaos, a sort of blending of heaven and earth. The products of Uranus and Gaia getting busy with one another were the other Titans. Uranus would destroy her children by consigning them to Tartarus, a prison and a place of torment. One of Gaia's children was Khronos (latinized as Chronus), who embodied time. Gaia convinces Khronos to castrate Uranus, and when she goes to meet Uranus, Khronos leaps out with a sickle and does the dirty deed, casting the genitals of Uranus into Chaos, the blending of the earth and the waters. As Uranus lay dying, he predicted that Khronos' own children would turn against him. It gets complicated though, because Uranus doesn't actually die. The children of Uranus are freed from Tartarus, but Khronos, now the king of the Titans, imprisons them all again, except for Rhea, who becomes his wife. Whenever Rhea gives birth, Khronos swallows the child. But Rhea hides Zeus from him, and instead presents him a stone wrapped in a blanket. The only Olympian not created in this manner is Aphrodite, who is born from the semen of Uranus after his castrated genitals are thrown into the waters of Chaos. There are conflicting stories about all of these events, including how Zeus grew to adulthood. When he did, he forced Khronos to vomit up his siblings (there are conflicting versions of this, too). These became the Olympian gods and goddesses. They went to war with Khronos and the other Titans. The defeated Titans were imprisoned in Tartarus (i guess it had a revolving door). Two of the Titans, Promethues and Epimetheus, took no part in that war, and so were rewarded by being given the task of giving the various creatures their signal qualities--speed, strength, courage, stealth, etc. Epimetheus doled out these traits, using all of them. In the meantime, Prometheus had fashioned man from the mud, and Athena had breathed life into him. (Another betrayal--Athena was the daughter of the thoughts of Zeus, and had sprung full-grown, as well as fully-dressed and wearing armor, from his forehead, and was to have been, basically, his bodyguard). Epimetheus had given out all of the goodies to the other animals, so Prometheus gave man the ability to stand and walk upright (like the gods), and then stole fire from the gods and gave it to man. For that, the was chained to a rock in the Caucasus Mountains where each day an eagle tears out and eats his liver, and each night it grows back.

It has been more than 40 years since i read all of this, so i might have many errors in that narrative, although i'm certain about the part regarding Prometheus, Epimetheus and Athena. You've got enough clues there to search online and come up with your own narrative. You may have though that you were asking a simple question, but you are mistaken.

Lisa, just be careful not to be mislead by false comparisons of the two

Jaroslav Pelikan, What Has Athens to do with Jerusalem? Timaeus and Genesis in Counterpoint

The similarities are now called into question. And of course Genesis predates Plato by many centuries.