It's a pity that you will go just before shad season opens. I suggest you go to the local tackle shop and ask around what biting and where.
Last time I went down there, we tried real hard from Orange Rocks (from Uvongo towards St. MIchaels on Sea, at the Corner of Hillcrest and Orange Rock Road, you will see benches from the road when looking towards the ocean) and the pier at Uvongo (got quite a big run there, but probably a flat fish). It seemed pretty safe too. I heard you should be careful going to Margate Pier. When we were there last December a guy got stabbed in the toilet.
If you are more experienced there's a place just up the road from Orange Rock which they call the Pothole, which will get you into deeper water. I personally did not try at Pothole, since the sea was very rough and I respect the tide too much.
Then at St. Michael's on Sea, from the rocks just past the tidal pool you will probably also stand a good chance to catch something. I heard they caught a couple of nice kingfish there last year.
At most of these places you will probably stand a good chance to hook on some karenteen, black tail and shad. At Pothole you stand a better chance for Kob or musclecracker is the water as deeper. Orange Rocks have delivered garrick, kingfish and yellowtail in the past. At the Uvongo pier (I think this is safest and easiest way to go) you can get shad, mullets, garick, kingfish and probably some flat fish, and if you are lucky, maybe a kob!
ENjoy your trip!
There is also a lot of info on here on Natal fishing. just dig in and you will find the good posts too!