It's normal to see an increase in fluid weight when you are new to exercise (or anytime you increase the duration, intensity or type of exercise you do).
As far as exercise and weight loss, weight loss more comes down to how many calories you eat. That's where the saying "abs are made in the kitchen, not in the gym " comes from. If your total calorie burn is 2000 cals and you eat 1500 cals consistently, you'll lose weight. If you exercise and increase your total calorie burn to 2400 cals but then eat 2400 cals consistently, you won't lose anything. Another odd thing that can occur is that you exercise and increase total calorie expenditure to 2400 cals and then continue to only eat 1500 cals and you find you eventually plateau. This sometimes happens when you're eating too few calories for how many calories you're burning, you may find you need to increase your calories slightly when you exercise.
It comes down to finding the right balance between your diet and exercise where you are consistently losing weight but not feeling deprived or overtraining (which can lead to an increased appetite and overeating).
