Gravity-Your mass/you and the Earth are attracted to each other . This lets you walk and not randomly just fly off of the ground.
Friction-This force lets people move and stop. Without it, we would have to push off of something to move and hit/grab something to stop.
Air Resistance-Air resistance slows your fall, yet very minimally. It works more on objects with more srea and less mass such as your hair and a sheet of paper.