Don't worry my son did that too. Their just use to being on their stomach so they want to be picked up and when you don't pick them up they get mad. What I do is prop him up with a small pillow under his chest so his face isn't in floor and put on some cartoons
They all hate it at first. You just gotta continue with it. My son will be 3 months old on Thursday and he's already pushing with his feet trying to scoot around lol