How do you think Humanity started on Earth?

The current scientific thinking has it that quasi-organic molecules over the course of millions of years in favorable environments organized into more complex structures that had the benefit of self-preservation and replication. The evolution of viruses (e.g. SARS-CoV-2) and prions today illustrate that process. 

Easy:

inanimate elements --> single cell life forms --> multiple cell life forms --> flora and fauna --> primates --> hominids --> homo sapiens --> humanity  And all this from the single cells on came about by evolution to improve survivability of the species.  NOTE:  Humanity is not a species it its the behavior of the species based on mores, beliefs, ethics, and history.