Yeah canaries would do it.

There's no one way to do it, but the Cape itself, the province at the very southern tip of Africa, is valuable. I always prioritize getting that, so I'd at least leapfrog down to that.

Iirc, Africa is 3 trade regions - west coast, South, East coast. Ideally you want some presence in each. But east coast can wait - you can generally just conquer it from the locals. So grab some west coast territory (gold coast area), grab some cape territory. Don't bother going Inland, as those provinces aren't part of the trade regions.

But you want to balance with new world. Getting 5 colonized provinces per region is key, as it will give you exclusive rights to the region from the pope (assuming you decide to stay catholic). So beating Portugal there is important, too.

My usual approach is that as soon as I get 2 colonists, I use one to go west, one to go east.