Okay kiddo, let's talk about how people moved around the world long, long ago, way before planes, trains, and automobiles!
So, a long time ago, when there were no big buildings or cars, people lived in small groups in different parts of the world. These people were called pre-modern humans. Some of these pre-modern humans started to move from one place to another in search of food and better living conditions, which is called migration. They didn't have any maps to help them find their way, so they had to use things like the stars and landmarks to find their way.
Some of these pre-modern humans lived in Africa and started to move to other parts of the world, like Asia and Europe. They did this by walking for long, long distances and crossing rivers and mountains. It was very difficult and took a very long time, but people kept moving in search of food and a better life.
Over time, pre-modern humans started to adapt to different environments - like cold weather or tropical climates - and they changed the way they looked and the way they lived. For example, people who lived in colder areas developed thicker skin and hair to help them stay warm. And people who lived in warmer areas developed lighter skin and enjoyed eating fruits and vegetables that only grew in those areas.
All of these migrations and adaptations happened a long, long time ago and helped pre-modern humans spread all over the world. It's really fascinating to think about all the different ways people lived in the past and how they eventually came to live in the places they do now.