The stage of human social development and organization that is considered most advanced is called Civilization. When people are called civilized they have organized such as town, not in small tribes or family groups.
You need to improve clarity in this introductory paragraph. Improve the presentation of these ideas.
The Egyptians were the first ancient people in the world according to research.
.... they are the first civilization as per the research. Not the first people... there is a big difference in these two interpretations.
The Egyptians were the first ancient people in the world according to research. Egyptian pyramids were built around 2500bc. Indus River valley (this was a third civilization that) focused on soil and agriculture that helped civilization settle down instead of being normative.
What is the link between Egyptian civilization and Indus? You need to establish the link and let your ideas flow in a more logical sequence.