How did you get to compete in the ancient Greek Olympics?

Answer 1

First, you had to be able to get there. Travel was slow and expensive, so only rich people and competitors who were subsidised by rich people or by their city could afford the travel and the time off work.

To be allowed to compete, you had to be male and (it seems) young, and able to speak Greek. Except that women and older men were allowed to have horses they owned put in the Chariot Racing (the prize went to the owner of the horses, not to the charioteer).

You had to be able to speak Greek, at least to the extent of reciting a prayer to Zeus in a decent accent.

You had to swear and oath before the statue of Zeus, in Greek, that you had been in training for ten months.