The lifeguarding class will also teach you your duties and responsibilities. Failure to execute everything you are taught in the class properly can result in negligence and lawsuits. After taking the class you are considered a trained professional and you have an obligation to help a struggling victim.
Your Lifeguard certification class will end with a test itself to prove that you actually are capable of saving a life if required. This is absolutely essential because it is very likely that you will have to perform at least one rescue in your career even if it is only a minor rescue. Passing this test can be difficult depending on which company is giving the certification. Keep in mind that you should study the book and notes throughout the class so that you will be able to pass this final test.
The lifeguard certification generally does not teach you how to work the pumps, treat the pool with chemicals, or clean the pool.
Once you do get your certification, it is time to start looking for a job if you do not already have one. It is recommended that you get the job first so that the company that hired you will pay for the certification test.