Diwali is the Indian New Year, which celebrates the victory of good over evil, and the pathway to light and virtue. It's also called 'the festival of lights' because of the tradition of turning on lights or lighting candles. You can go along yourself to celebrate this New Year as well as the ritual of Pooja, an act that pays homage to Lakshmi, the goddess of prosperity.
If you want to participate in the ceremony, you can do so by giving your own offering to the goddess (fruit, flowers, candles, or a golden object). You'll receive a Bindi (a dot of red on your forehead) and a Kalava (protective red thread) to wear around your wrist. Everyone will light candles together to symbolise the knowledge gained by having inner peace in the face of ignorance. And afterwards there will be a festival of Indian dance followed by the chance for everyone to dance to India's current musical beats.