About swimming

Question
1.How to  be calm and relax in swimming?
2.How can I be fitness for swimming?
3.What kind of food can I eat for this sports(swimming)

Answer
Hello,
Practice is key to being relaxed in the water. I would suggest for fitness (non-competative) to try to do laps daily and increase gradually the amount of the laps that you do over time. Finally maintaining a healthy diet will help with muscle mass and endurance in swimming.

I'm sorry I do not have a better answer.