How did the war between Native Americans and colonists start and why?

There were many battles between the Native Americans and the British and their colonists. Most Native American tribes didn’t trust the British nor the British colonists, but many of these tribes were friendly with the French. The French made it clear that they didn’t want to take Natives' land. They also married some Native American women and converted them to Christianity. The French were also interested in trading with the Natives.
The British and their colonists wanted to control more land. They often clashed with the Native Americans in battles for control of land. The British had no interest in marrying the Native Americans, and they didn’t try to convert them to Christianity. British policies toward the Native Americans treated the Native Americans as if they were a conquered people.
Pontiac’s Rebellion, which began in 1763, was an example of a conflict between the Native Americans and the British plus their colonists. After the French and Indian War ended, the Native Americans feared that the British would expand beyond the Appalachian Mountains into lands the Natives controlled. The rebellion, which was eventually ended by the British, showed that the frontier wouldn’t be quiet and that relations between the Native Americans and the British and their colonists weren’t very good.
https://www.history.com/topics/native-american-history/american-indian-wars

https://www.thoughtco.com/pontiacs-rebellion-an-overview-2360770

https://www.u-s-history.com/pages/h598.html