Diet: Strengthen the intake of protein vitamins (beneficial to muscle gain) and reduce carbohydrates (beneficial to weight loss).
Muscle-building powder \ Creatine can be eaten in moderation, too much will increase the burden on the liver and produce side effects.
Besides, with your height, your reasonable weight is about 73 kilograms.
The practice of reducing abdomen is mainly aerobic training, supplemented by the training of waist and abdomen muscles, and it is necessary to train with small strength and multiple times, and also to cooperate with static exercises.
Finally, I wish you success!