If you want to buy bitcoin in Africa your best option will most likely be to use the global peer-to-peer bitcoin exchange LocalBitcoins.com as it is one of the safest and most-used bitcoin exchanges in the world.
If you are a freelancer or a remote worker based in Africa and you are (or want to be) getting paid in bitcoin, LocalBitcoins is also a great place to convert your bitcoins into local currency.
LocalBitcoins allows users to buy and sell bitcoin with local currency using bank transfers, mobile money transfers (such as M-Pesa in Kenya for example), PayPal, gift cards and even cash when dealing in person.
While caution is always advised when trading bitcoin peer-to-peer, the platform actually uses a reputational scoring system that rates traders on LocalBitcoins and, thereby, ensures a strong degree of safety. Furthermore, it also an escrow account. So if you are selling bitcoins for local currency, you don’t release your bitcoins from your LocalBitcoins escrow account until you have received the local currency payment.