Throw your clothes into a pile on the floor, and the clothes will still be there until someone deecides to pick them up. These two observations are considered part of Newton's first law. But wait a minute. Everyone knows that a ball rolled forward along the ground won't keep moving forever. There are forces in nature that will interfere with motion, and one of these forces is friction.
Friction slows things down.
It happens when you scuff your shoes against the floor, or when the tires of your car meet the road. You know, its that big round machine that turns around, faster and faster and faster, until you feel like a piece of wet laundry pinned to the inside of a washing machine set on the spin cycle. I get dizzy just thinking about it. Imagine tying a length of string to a stone and whirling it around above your head. It's really the force exerted by your hand tugging on the string that keeps the object moving in a curved path.