1. Saturn did not make the LS2 until 2000, you probably meant the SL2 2. If reverse is gone it's probably either the clutch pack or the valve body. Either way, you'll need to take the vehicle to a transmission shop.
The camshafts are at the top of the head(s). Pull the valve cover(s) and you should see the camshaft(s). Some of the 4 cylinder Saturns had only one camshaft. The DOHC Saturn (sl2) and the LS2 had had 2 camshafts in the heads, meaning that the V6 LS2 had a total of 4 camshafts.