How do I explain the laws of motion when I am walking down the street?

-- If the person to whom you're explaining them is alongside you, then you should adjust your walkiing rate to match his, so that he remains within earshot for the duration, and receives the benefit of the complete explanation.-- If you're presenting the explanation on the phone, then your walking rate doesn't matter.  But you still must adjust it to avoid running out of breath as you speak, and you must also maintain your own awareness of your surroundings, so that your explanation is not inadvertently truncated.

Well one way that you could explain is well by just walking and just say that one of the laws is an object in motion tends to stay in motion. The you could punch the palm of your hand ad then say that and object will stop if hit with an unmeasured force. You could also drag your feet on the sidewalk and talk about how friction stops an object from moving.I hope that this was helpful to you.