Africa is not homogenous.
If you mean Namibia:
The prices are very high. Budget 1000$/day.
Only operating start of November to start of January.
If you are used to flying Midwest you're probably used to the terrain (unlandable), which is the first problem many people struggle with.
You certainly need to be of a level of competence (for solo flight) where in homogenous soarable conditions you are never going to outland, and you can identify the onset of unsoarable conditions at least an hour or two ahead.
You will need to be comfortable and competent operating a self-launching motorglider (likely a SOLO 2625).
All the sites are full-service and will sort out and smooth over any licensing issues with enough notice.
You'll survive at any site with only English, they all have advantages and disadvantages, but In My Humble Opinion (many will argue with me on this), the most English is spoken at Kiripotib, Bitterwasser is the most populous and Veronica is the most XC-focused.
They can all offer you some degree of coaching, whether that means a backseat pilot or help on the ground may vary. It may be more fun to go with a more experienced friend.
I have been twice, first trip was 9 days, 7x >1000km flights. Second trip was a bit harder, we went for three weeks and only managed 1000k on about half the days. You can get unlucky and get a 10-20 day run of bad weather, but it's rare.
I don't recommend flying the single-seaters, it's too much fatigue if you're expecting to fly every day. There is very little else to do but fly.
If you mean South Africa:
It's largely club operations like elsewhere in the world. I hear good things about Soaring Safari's which is more commercial and catering to tourists. All summer flying.