Genesis means the beginning. People have wondered about the beginning of things down the ages. Today scientists make up theories as to why things should happen, but in the past people had much less evidence to work with. So they made up stories that they could understand and that partly, at least, could be connected to what they saw around the.
All regions have a genesis story of some kind. They were made up thousands of years ago. If you do not take the story literally, but instead look to the purpose of the story, you will often find a moral lesson in it. These moral lessons are still often important today.
Most people recognise that, for example, Adam and Eve, is a made-up story from ancient times, but the idea of not giving way to temptation (eating the apple when told not to) is an important story to help people live together.
Scientists looking for genesis have so far traced back out origins to the Big Bang, over 13 billion years ago. But they do not suggest this is the beginning of things. It is just as far back as we can see. The origins of the the universes and everything are just as wondrous and unexplained today as they always were.