A burqa is a garment worn by women that completely covers them. It is worn for religious or cultural reasons, and is only worn when the woman is outside the privacy of her home. The veil part of a burqa is called a purdah, and may cover her entire face or just the part below her eyes.
Fireworks are a kind of explosion that is designed to explode into a specific pretty pattern and nice colours. At special events, there are usually big displays of lots of different fireworks.
A smirk is a smile that is smug and slightly offensive. People often smirk at you when they think they know better than you do.