Koshka! I did exactly the same thing in Oct 2010 ...
Camped by myself in Kruger (but only for 3 weeks, not 5!).
It was the 1st time I'd ever been camping (apart from 2 organised tours).
I didn't want to splash out too much in case I didn't like it.
I had a tiny 2-person tent (R200!) into which my single inflatable mattress just fitted ...
And I realised after inflating it the first time that I had to do this inside the tent as the inflated mattress didn't fit thru the tiny door!
Like ur plans, I was out every day, all day, and my tent was only used to sleep in - it was fine. (check out my trip report from that adventure viewtopic.php?style=2&f=27&t=48237
The weather should b nice ... that said, u can get extremes ... 40 degrees one day and 16 degrees the next so bring a sweatshirt & a light rain jacket/windbreaker for the cool days!
I also found that long cotton trousers for the evening were great as they prevented mossies (but do buy anti-mossie stuff as well and apply it liberally at dawn and dusk).
A coolbox is a must ... As Hugh told u, fridges/freezers are NOT available at most of the campsites but u can buy ice in the shops to put in ur cooler box & keep stuff cold.
Meat can be bought in the shops but I have seen too many people buy meat then find it is completely "off". If u want to do meat braais, do those when ur are in P'kop, Croc Bridge, Lower Sabie, Skukuza where u can pop into town quickly (and not waste too much park time!) & buy meat ...
If u bought frozen stuff it would prob last a couple of days in a cooler box with ice but I wouldn't trust it much longer ...
A hammer & long nails was one of the best bits of advice I got when posting a similar question seeking advice before I went camping ... The ground will b very hard and a mallet & tent pegs may not work.
Definitely take a sleeping bag, it does cool down at night; a camp chair is also a must but u can get cheap ones here for about R100 that will work!
To recharge batteries, etc, u can either use SA electrical sockets in the kitchens & bathrooms or get a caravan plug for use in the campsite.
Will u b camping at a powered site?
U will need an extension cord as well if u r as the electrical boxes can sometimes b a distance from where u get ur tent set up.
A headtorch/flashlight is def recommended.
I would buy a plastic plate, bowl, knife, fork & spoon, a sharp knife & a chopping board, a bottle opener/corkscrew (very important!) a can opener; washing up liquid, a sponge, a couple of T-towels, clothes pegs, string (very useful for a number of things, including a washing line) canned meat, fish, eggs ... a stable Kruger food, a little saucepan and maybe a little frying pan too.