There is a lot of information available on Native Americans, both on the web and available in books. This list is by no means exhaustive but a productive "first deep dive" assemblage for anyone interested.
Fascinating Details can be found by searching for and looking at old maps. There is so much you can learn!
A few sites/pages I have authored. Growing up in Iroquois Mohawk lands probably put the bug in me to pursue this topic...
A starter list with 3 must reads!
These are available on YouTube and extremely well done. Try to find the time to watch (especially How the West Was Lost) .