The ancient Greeks worshiped their gods every day. They believed in a great many gods! The ancient Greeks built many, many temples. They believed each temple they built should honor only one god, no matter how big or elaborate the temple. Some cities built more than one temple to honor the same god. Women could be priests. Priests were assisted by attendants. People would bring offerings, usually food, to the temples when they prayed. This food was collected, sometimes stored, and eaten by the priests and the attendants in honor of the gods.
Sacred sites were located all over the place. Sites held a simple alter at which the ancient Greeks could pray. Some sacred sites became so popular, for whatever reason, that a temple was built on the site.
The Greeks also prayed at home in their courtyards. It was not unusual to pray at home, stop at a sacred site, and visit a temple, all in the same day.
The Greeks held festivals to honor their gods. First a festival, then a parade to a temple, then a sacrifice - an animal of the same sex as the god being worshiped, and then a feast. They held sporting events, like the ancient Greek Olympics, to honor their gods. In ancient Greece, honoring the gods was part of daily life and part of just about everything they did.
The Greeks did not believe their gods lived in the temples or at the sacred sites. But they did believed the gods visited these places, and had magical powers that could hear their prayers. The Greeks also believed they could ask for help and advice through an oracle. An oracle was a wise woman with the ability to see the future.