If the plane is hard to push, you are working yourself and the plane too hard, as a series of light strokes quickly done will surpass heavier work in less time, and give better results. If it is hard to push, raise the blade by striking the metal post at the back of the plane body and tap the wedge to lock the iron in place. If the plane is not working hard enough, then tap the top of the iron very slightly with a wood or brass mallet to take a deeper cut. As with all hand-tool operations, less said and the more done is best. You will learn more by doing than what I can tell, and if I play teacher for a moment, I'll remind you that the best teacher would be 1-2% instructor and 98-99% encouragement and role model.
Last Wednesday, one of my third grade students noticed how easy sawing wood has become for her. It is important that children get a sense that things get easier over time and just because something was difficult at one time, it will not always be that way. Unfortunately, much of education does not impart to each child their own sense of unlimited potential.
Reading is very much a matter in the same book. Some children do not read as easily as others, and yet schools treat kids as stupid if they are not reading at grade level. Just as in sawing, as muscles grow in strength, and the control in the hand becomes easier, in reading the brain matures, the eyes learn to better track letters on the page and children learn to connect what they've read with their own experience. Putting huge pressure on kids is like trying to plane with the iron too deep. You'll come to the conclusion that there is something wrong with the tool or the operator, when the sole problem was failing to have it set at the right depth.
Make, fix and create...