What year did Plato start teaching?

The Academy (Akademia) in Athens was created by Plato around the year 387 BC.

Though the Academy was essentially a school, it was not a school in the traditional sense of the Word. There is little evidence that there was actually any sort of set curriculum. Rather, Plato would bring up questions through lectures that he and his students would consider philosophically, ethically, and rhetorically. It is also likely that they discussed mathematics and scientific concepts like the motion of the planets.