Well one thing is def water and lots of (depending how much you drink) It gets how pretty hot out there and staying hydrated is paramount. Also a basic tool kit including chain tool, tube or slime, some allen wrenchs, and perhaps a pump. Snacks are good too I love cliff bars, but what ever floats your boat there.
As far as pace, pick one! Swamp has groups for every pace. If you are brand new i would recommend c group slow to moderate pace and they make stops at all intersections for everyone to catchup and take a break, if you find that too slow, there are the b groups, and if you are crazy there is always a. Talk to the ride guide when you get there to get an idea of pace and the trails.
Hope this helps!