Help reading mfp app

nikkit3

So, I'm trying to understand the way you read and keep track of calories on my fitness pal.
I don't understand the net calories and then also when you add exercise I don't know why it gives you more calories to eat ? I'm confused. Also when you fill in your activity level, is this with exercise or not exercise included.
Oh an can you acces the MSG boards from the app on your phone ?
Thanks