If we assume that Columbus' silence deters Iberian-funded explorers from embarking on the same, apparently suicidal, adventure, then the completely different direction of European conquest has
massive knock-on effects for the natives and Euro-Americans both. Eastern Canada was, obviously, far less populated than the Caribbean and not really good for much save fish and putting undesirables somewhere, plus it didn't happen to be a perfect staging ground to conquer an immensely rich empire that was in constant crisis and despised by all of its neighbours. If Spain and Portugal only hear about the Americas from the English saying "
so much cod!!! not much otherwise", then they'll probably delay significant investment for a little while and end up starting off in Brazil, rather than the Caribbean. So the original wave of Europeans lands in two places - Newfoundland (which might, in a nice twist of history, be called "
Brasil") and Bahia - neither of which is anywhere near Central America, where the OTL Europeans pulled off the ridiculous stuff that eventually landed them total control over both continents.
The native peoples of the Caribbean, unfortunately, are still pretty much screwed; there's really no way to stop that in a timeline beginning after, like, 1000 AD. But Mesoamerica and the Andes are a lot more promising. The Aztecs are still going to collapse, and spectacularly, but having them collapse solely due to neighbouring rivals and not an alien power is going to be interesting - and probably a lot better for native Mexicans in the very long run, since we can assume the European conquistadors actually benefited from fighting a single hegemonic state instead of groping around in the total chaos that a post-Aztec Meosamerica would be. Then the conquest of Peru was just dumb luck and wouldn't be reproduced (as such) in 9/10 timelines. If either is to be conquered (Mesoamerica quite likely anyway, Peru maybe not), expect them to be more "India" than, well, "America": trading posts, missionaries, native collaborators, officers taking the initiative, and a gradual, sleepwalking conquest rather than a coup de grace. And that's not even getting into the native peoples of North America, who will have an interesting time of history to say the least.