What was the first life that appeared on earth?
The first life would have to have been a functioning cell with the ability to reproduce containing either RNA or DNA
No one knows what the first life was, where it originated or how.
The early theories of a warm shallow pond have been largely abandoned.
The idea of life starting in clay crystals has lost popularity.
The most popular theory today is that life started in volcanic vents deep in the ocean.
All theories of the first life have to grapple with the question of information. The first life would have to have sufficient information to regulate its biological processes to overcome entropy, and at the same time have the information required to copy and transmit that information on in reproduction.
At this time information theory and mathematical models make any known natural process unlikely to result in a functioning living cell.