Confidence on one sport will transfer to the other sports as you become form familiar with them. Below is a course outline to help you get started after each lesson you will be given a set of exercised to comple. If you are a proficient swimmer you can just bypass this section. The swim poses a unique challenge to the athletes. Unlike running and biking shear volume of training may not make you faster, and you fitness level will have little to do with your speed in the water.
Swimming is all about technique.
This is not to say that swimming does not make you physically fit, it does, only that an out of shape athlete that knows how to swim properly still swims circles around a triathlete who spends an hour every day in the pool doing laps. If you just want to complete the distances for the triathlon then, jump in the pool and swim till you feel tired. This may only be one length of the pool. Do not get frustrated especially if you have just pulled off a sub one thirty half marathon and feel fitter than ever before. Once you get your swim rhythm you will feel great.