There is no absolute static exercise method (except drugs), and your situation is not bad. As long as you exercise properly, you can basically achieve your goal. I suggest you take silent exercise as the main exercise, supplemented by swimming.

1, dumbbell exercise (weight 1.75~2.50 kg): Exercise is simple and easy, not limited by venue time, and the method is simple and effective. Persistence can make the chest muscles firm, which can effectively achieve the effect of expanding the chest and help reduce the fat on the shoulders; There are many specific dumbbell exercises, and you can find the one that suits you online.

2, swimming: swimming has the characteristics of fun, swimming is to overcome the resistance of water rather than gravity, muscles and joints are not easy to be injured; When swimming, under the action of water, the whole body is fully exercised, so that the blood of the limbs can easily flow back to the heart and the heart rate is accelerated. Persisting in swimming for a long time will increase the activity of the heart and make it contract strongly. Through water pressure, you can massage the chest, which is very effective in reducing the fat in the abdomen, chest and shoulders. It can make the lines of the body symmetrical and clear, and with your dumbbell practice, the effect of two-pronged approach is obvious.

I wish you success in fitness!