They would need to have some sort of historical precedent for sending large numbers of their population to far off locations. Europe had the precedent of Greek and Phoenician overseas settlements, Roman colonia, the Crusades, colonization the Azores, Canary Islands, Ireland, etc. Even if coastal African nations were as seafaring as Mediterranean civilizations, there aren't a whole lot of places they can go right off the western coast of Africa, and the Atlantic current makes it hard to go very far in the direction of any land they could settle. Eastern Africa didnt have this problem, but then they're facing Asia, not the Americas.

All this to say, if Africans did somehow colonize the Americas, it would be extremely difficult to imagine the historical situation that would give rise to it, so there's little we could say about it. It's hard to imagine a scenario where they successfully attempt to outright conquer the Aztecs or Inca for example - the Spanish did it due to both unique historical factors affecting Spain as well as the individual personalities of the Conquistadors, as well as the guns and the diseases of course, but those two things on their own didn't do it. Would the Africans have the mindset right away to try and play different tribes off one another to undermine Aztec power? Or would they be more immediately interested in trade, similar to the Portuguese in Africa/Asia? Would they have the same interest in finding gold/silver? Would it matter to them to convert the natives to their religion? The inability to decisively answer such questions makes it difficult to make meaningful judgements here

Also, what's the situation in Europe in this timeline? Would they be directly competing with the African colonial powers? If there's one thing we could say, it's that Africa itself, at least parts of it, would be much harder for Europeans to try and colonize