How did the early people travel to America?

For many centuries, anthropologists have focused the research of early human migration on the Bering Land Bridge, a strip of land that would have connected Northern Asia to North America and Canada. Researchers believe that the migration would have taken place around 14,000 years ago, at the end of the last Ice Age. Sediment layer samples taken from both sides of the Bering Strait confirm that early humans may have lived on the land bridge itself for hundreds of years before branching off to the northern, southern, and eastern parts of the continent.
In 2016, the University of Copenhagen's evolutionary geneticist Eske Willerslev postulated that if the timeline of human migration to North America is correct—and most scholars agree that it is—then the Bering Land Bridge would have been inhabitable due to its climate. While Willerslev does not have an alternate explanation, he suggests that glacial masses could have moved humans from other parts of Asia and the South Pacific to North America and South America's Pacific Coasts.
While Willerslev's hypothesis may open exciting channels for new discoveries, for now the Bering Land Bridge theory remains the one commonly accepted by scholars.
https://www.history.com/news/new-study-refutes-theory-of-how-humans-populated-north-america

https://www.nps.gov/bela/learn/historyculture/the-bering-land-bridge-theory.htm