No one knows an exact time or date the Ancient Chinese first use Chopsticks, but it certainly was a long time ago.
Most likely when the first person was cooking the first slab of meat in a fire and needed something, a twig or stick, to pull it out.
Chopsticks are first mentioned in a book called Liji, the Book of Rites, which was written around 2,000 years ago.
But historians seem certain that they had been in existence for thousands of years prior to the publication of that first reference.