Run away :To escape or flee from a place or situation.
The child decided to run away from home.
Run into : To meet or encounter someone by chance.
I ran into an old friend at the grocery store.
Run off: To leave quickly or suddenly.
He ran off without saying goodbye.
Run out (of) :To use up or exhaust the supply of something.
We ran out of milk, so I need to go to the store.