I would recomend learning about their mythology, there are many english sources online, you could start with Wikipedia (which is full of related articles).
The Mythology of those deities are took among many different sources; poems, pieces of theatre, novels, philosophy/history books, so you can navigate among different articles/texts and learn a lot about it.
The 5th century of Old Athens is one of the most well-pictured epochs of antiquity by the high number of authors texts which were preserved of this time. I would recomend start with Plato, for example, which has more than 20 books picturing much of the "way of life" of his epoch -when those Deities where intensely reverenced.