“And God said, ‘Let there be light’ . . . and there was light. God called the light ‘day’, and the darkness he called ‘night’.” Genesis 1:3, 5
The Bible does not tell us how long ago the earth was created, nor how long that process took. It does not tell us exactly how the earth was made. Genesis 1:1 tells us that in the beginning the earth was. There were neither mountains nor valleys, trees nor shrubs, rivers nor oceans. The earth was empty and shapeless.
The Bible does tell us about the six creative days in which God prepared the earth as a place to live for mankind (Isaiah 45:18). And it gives us the length of the seventh creative day: seven thousand years. It may be that each of the creative days was the same length of time, forming a creative week.
At first the earth did not have a definite shape—it was just a mass of material spinning round and round. As it spun, we believe its water and minerals were thrown off as gases. They then cooled and took the shape of rings around the earth. As the rings would take shape, so would the earth. It would have begun to look more like a ball than like a messy lump of formless elements. And as the mess took definite shape some light shone onto the earth, possibly similar to the Aurora Borealis (lights in the night at northern latitudes caused by electrically-charged particles from the sun). Sunlight, as we have it today, was not seen until the fourth day, but there was some light. The earth began to look more like the globe we know.
Our universe is still developing, and scientists spend much time studying and trying to explain creation. When they learn a new fact we can sometimes find a Scripture that also describes that fact. For example, Job 26:7 tells us the earth hangs in empty space.
Men do not understand all Scripture, nor do they understand all about creation, but God gave us the Bible and planned the creation of the universe. So the Bible explains creation correctly, although briefly, when it speaks of it.

Our universe is still in the process of developing.
Link to supplemental lesson worksheet: www.blessedbible.com/linked/a2z-lesson-2.pdf