how do spray bottles work??

Answer 1

Before you start pumping, the gun is set for a downstroke, not an upstroke (the piston is sitting outside the cylinder). When you first pull the trigger back, and the piston pushes in, there is no liquid to pump out; there is only air in the cylinder chamber. The piston has to slide out to suck any fluid from the reservoir.
On this first upstroke, the pump starts sucking the cleaning liquid from the reservoir. But it also sucks in any air sitting in the plastic tube leading to the reservoir. Before you can start spraying the cleaning liquid, you have to drive this air through the pump mechanism. This may take a couple of downstrokes and upstrokes.
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Answer 2

this is a guess. the straw is connected to the spray thing and is inside the bottle (duh) but when u push on the spray button thing at an angle(pointing down) the spray thing has little holes in it to spray a mist.