The safari is a really neat attraction. There are places that the vehicle will slow down and actually stop so there will be opportunities to take pictures then. If you have a long range zoom, be careful because you tend to get more motion the further you are trying to go. Otherwise, if you have a shutter control, set it for a fast speed.
Another tip, this happened to me and although it was a camcorder, it could also happen with a digital camera. I was getting a "moisture present" display on my screen. Due to the high humidity in Florida, moisture collected on the camcorder battery. I went nuts trying to find out where the moisture was but finally figured it out. It was as simple as wiping off the leads on the battery with a napkin or towel, shirt, pants etc.
Have a great time.
Adam aka Big Dude