I'm a female, 172 pounds, 5'5 feet. I know I'm overweight and I decided to change so I'm thinking about starting swimming classes.

Are they good for which bodyparts? I want to lose these flabby arms and thighs, I feel ashamed with my ass exceeding a seat... also I heard it improves your breathing or something like that, is it a good exercise to lose weight?

I already bought a swimming suit and those glasses, would I need anything else? I plan on getting serious in this so I want to have everything that'll be necessary (like those silicon earplugs, are they useful?).