What is the best non-English language in...

Yes–it doesn’t make sense to lump all of Africa into one. It doesn’t mean much to say someone is “traveling to Africa.” It’s so vast and varies so much that it’s meaningless. It’s like “traveling to Eurasia.”

So it really depends on what part of Africa you’re going to. In the North, you’re better off with Arabic, and in the East, Swahili.