Experiences that made you think that air exerts pressure:
(i) Balloons and balls can be used only when they are inflated with air. When the balloon is overfilled with air it bursts due to excessive air pressure.
(ii) Blowing air can move curtains on doors and windows.
(iii) Cycling against the direction of the wind, it is difficult to ride. It shows that the air exerts pressure.
(iv) While rowing a sailboat in the direction of the wind, it is always easier to row and while rowing a sailboat against the direction of the wind, it is very difficult to row. It also shows that the air exerts pressure