Bring casual, comfortable clothing and preferably light, long-sleeved blouses and lightweight trousers for protection against the sun and insects. Don't forget:
Sun block, sun glasses, good walking shoes
A light and compact raincoat
Swim suit
Torch
An elegant outfit for a cocktails
If traveling with an organized safari, see if there is a weight limit, in which case you may have to restrict your luggage to 10-12kg.