Your body will need time to adjust to the new demands you are placing on it. Most researchers believe that the first 4 weeks or longer of resistance trainer is mostly neuromuscular development, meaning your body is learning how to use your muscles and recruit more fibers to increase strength. Do not be alarmed if you do not see your muscles getting bigger right away. Everyone responds differently to training. Some people will increase the size of their muscles, while others will see an increase in strength, without a corresponding increase in the size of their muscles.
Weight loss takes some time.
Do not expect to lose 15 pounds a week. A loss of 1-2 pounds a week is reasonable. Losing too much weight too quickly not only increases the chances it will be gained later, but it is harmful for your body as well. Remember that muscle weighs more than fat. This is okay.