New peoples appeared on the planet for several reasons. The first is the long life of a certain number of people in isolation from the rest. Moreover, isolation can be both natural (for example, life on an island), and deliberate. In this case, over a long period of time, this group forms its own language, behavior, culture, etc.
The second option is a mixture of two or more existing peoples. In this case, each ethnic group contributes to the formation of a new one, which may have the features of all its constituent peoples at once.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.