A Force is the push or pull on an object. This means that if I am hitting a rock with a stick, and it goes flying, I am applying force to the rock using the stick. Net Force or N is the sum of all the forces being applied to an object.
If two kids both hit a stone with the sum of the forces being 100 N (100 Net Force) and both children are hitting the rock at the same force, then the force of each of the kids is 50 F.
When N is applied to an object, this said object will change speed. This change is the object's Acceleration (A). The larger the object, the more N is required for it to move faster.
For example, if you want to move a truck at the same speed as a Lamborghini, then you will have to apply more N to the truck rather than to the race car because it has a smaller mass than the truck and thus needs less N than the bigger vehicle.