I love to go swimming. I do it for recreation and for exercise.
I love swimming
Did you go through the process of swimming lessons to learn how to swim or did you learn on your own?
I am curious about other people's experience, I love swimming but never had the courage because a childhood friend once died in the swimming pool
I learned at a very young age, humans can hold their breath and do the swimming basics within weeks of birth, I learned at about age 4.
That's comforting. What's the level of chlorine in Swimming pool water that is safe for human consumption as water is easily been sipped during a swim 
I don't know the safe level but pools are regularly tested for chlorine and PH levels.
That's ok because I know sometimes people pee in the pools accidentally or on purpose so it's usually good to add some chlorine right?
Yes it's important to maintain the water purity to prevent transmission of waterborne diseases.