Day 1: Creation of light and separation of light from darkness.
Day 2: Creation of the sky (or firmament) to divide the waters.
Day 3: Separation of land from water, creation of vegetation.
Day 4: Creation of the sun, moon, and stars to govern day and night.
Day 5: Creation of sea creatures and birds.
Day 6: Creation of animals, including livestock, land animals, and humans.
Day 7: God rests, blesses and makes holy a day as sabbath.
So according to the creation account in the biblical text, light was the first thing created by God on Earth.