If your vehicle has a timing chain then it is not likely that it will need to be changed. Timing chains can stretch and loosen over time, but for the most part they are designed to last for the life of the engine. On the other hand, a water pump can fail at any time. It is normally recommended to replace the water pump when the timing belt is changed because the procedures are essentially the same and there's a significant cost savings when replacing both at the same time. However, since the timing chain would not need to be replaced then the water pump should not be replaced unless there is a problem. The water pump is not a normal maintenance item that needs regular replacement, however I would check your vehicle's owner’s manual to be sure on what needs to be replaced when.
The serpentine belts are the ones that drive the other components in the engine such as the power steering pump, air conditioner, and the alternator. These belts should be visible from the engine compartment.