New to calorie counting

Calories in > calories out = weight gain
Calories in = calories out = maintain weight
Calories in < calories out = weight loss

Your body needs fuel to function. If you put in too much fuel it is stored, too little and you don't function too well. Just lying in bed requires fuel! Until you're dead, your body is constantly using energy.

What did you tell MFP? If you gave it an activity level, and goal to lose X amount per week, you eat those calories plus any "earned" from exercise above your normal activity. The more extra activity you do, the bigger your OUTput, so the more you can put in the achieve the same result. You need the extra calories to help fuel your workout. Restricting calories too much and trying to be too aggressive with your loss will likely mean your body won't be getting the nutrients it requires to be healthy.

Get yourself a food scale and some measuring cups. Accurately weigh all your solid food (raw/pre cooking is best), measure your liquids, and log what you eat in to your diary. Try to eat predominantly nutrient dense foods, making sure you get some protein, fat and carbs. Many people seem to cut out fat as it is calorie dense - please don't! It is essential for good health, body function, nutrient absorption etc!

​Please see these articles, and many other helpful articles, on the MFP Help pages...
myfitnesspal.desk.com/customer/portal/topics/455841-general-questions-getting-started/articles