Native american immigration

I was wondering how long ago Native Americans immigrated to the Americas. I have heard sources saying anywhere from 9,0000 to 50,000 years ago. This makes me confused. Do you believe they crossed the Siberia Land Bridge? Another thing that is confusing is that some Native Americans say they have been in the Americas since the beginning of time and that they didn't come from Asia and cross the Siberia Land Bridge. I'm not sure what to beleive but even if they didn't cross the land bridge why do Native Americans say they have been in the Americas since the beginning of time if the Earth has only been here for 4.54 billion years? That would be impossible and humans have only been here for like 4.5 million years to make it even more interesting. Just wondering. I am doing a project on it and as I researched a lot of information seemed contradictory.

I dont believe in the land bridge theory, I believe natives (not eskimos) have been here since humans were created, we didnt come from anyone else, we look like no other race.

So did humans evolve from monkeys in Africa an North America at the same time? Just wondering.

my cultures belief is humans evolved from wolves, bobcats, ravens, not from one species, there is a whole bunch of stories about creationism in native culture. and like some legends involve animals becoming humans like evolution, and others the animals gave birth to humans, and taught them how to live,

No one knows when humans arrived here. The oldest evidence is dated to12,000 years ago, but it's possible it was longer than that.

TO Jaes:
So do you beleive in Creationism or are you an atheist because I've seen that you said you were an atheist on other post. Just wondering.

Humans evolved from earlier primates in Africa about 200,000.
Maybe humans crossed the Bering strait, from Siberia into Alaska during the last ice-age, approximately 20,000 - 30,000 years ago.