According to Newton's third law, if you push on a wall, the wall?

The wall will push back, in exactly the opposite direction, and with

exactly the same size force.

That's why the net force on the palm of your hand is zero, and that

in turn is the reason that your hand doesn't accelerate.

If you keep increasing the strength of your push, then eventually you

exceed the force that the wall is capable of delivering. Then the wall

crumbles and falls, your hand accelerates in the direction you're pushing,

and the crowd goes wild!

The wall will push back.