I'm still connecting back to one of my cultures but I've heard North America called turtle island. Though that includes Canada too, so I'm not entirely sure myself about a term describing just America. The closest thing I've heard from one of my aunties is turtle Island when describing pre-colonized america.
Though it probably depends on the tribe. As like many things it probably varies from tribe to tribe. But from what I've learned so far, the tribe I'm enrolled in doesn't have a word for america (or a concept like america). But rather has words for the surrounding land and tribes. I'm still relearning my language, but I haven't heard anyone use a word for america exclusively yet.
I've really only heard turtle island when talking about america pre-colonization, but a lot of my close relatives wouldn't know because they're not that connected either. Because America didn't have any foundation prior to colonization I don't think a lot of tribes have an equivalent for it. America is fairly new compared to the indigenous people in america.
From what I can recall though, we don't have a word that groups all Native Americans under one group of geographical divide other than maybe turtle island. But even then turtle island isn't what some tribes called what we would call america today. It really depends on the natives you talk to though.
i think one big problem with the united states is that they forgot to name the country