The only non-native people who reached the Americas before columbus were the Inuit, the vikings(who never permanently settled), and there's also some evidence that suggest polynesians may have reached the west coast of south america or at least had some contact with the people there, though this one is also largely in contention with new evidence suggesting otherwise.
All other claims are fringe and have never been taken seriously among scholars and experts in the field of pre-columbian Americas as there little to no real evidence to support it, and for more popular ones have usually had experts in the field come out and explicitly debunk it, ie white/european soltreans, black olmecs/washytaws, ming-chinese, 1149 muslims etc etc And pretty much are only touted today by members who share some kind of ethnic, racial, or religious ties to the subjects of the claim.
The truth is that the western hemisphere has been largely isolated from the eastern hemisphere aside few cases listed above before large ocean going vessels were built capable of traversing large bodies of water and storing enough supplies for the crew to survive on. And even then there would need to be some kind of motivation to make such a journey. The only other option would be ot cross the bering strait(ie natives, Inuit) or island hop in the arctic(vikings) Most societies didn't fit all of those criteria. There's a reason it was the last continental mass that human beings settled on. Even australia is more accessible.
And even then the native inhabitants of the Americas were one of the most largely genetically homogenous populations in the world due to their pioneering population being so small, with some genetic studies suggesting that the original founding human population consisting of only about 250 members.
https://phys.org/news/2018-05-dna-sequences-people-native-american.html
.Anything thats feels like a insult to your intelligence to just believe blindly is usually white science.