What are three components of a stall for aircraft?

Speed, weight, attitude.

Understand aerodynamics, you'll understand what to expect.

I cant think of 3  "components" but, several Causes:

1) excess angle  of attack

2)  airspeed below stall speed.

3) excess weight

4)load factor--weight & balance. This can cause excess pitch/AOA.

5) Center of gravity  location--again, affected by loading, affects AOA

5) low engine power ( a Cause of low IAS)

Stall is caused by lack of sufficient lift; in cases of excess pitch/AOA, the laminar airflow over top of wing breaks into turbulence, so insufficient vacuum atop  wing.  Way to recover is almost always to  pitch nose  Downward (Counter-intuitive) and increase engine power. With the V- Tail Beech "Bonanza", it was handled Differently. . That's why so many crashes with them.

Understand aerodynamics, you'll understand what to expect.

"Stall" is the loss of lift and it has to do with speed and just how far up your nose is pointed. Not being schooled as a pilot, I can't think of the third.

Just please let us know when and where you are flying- because I don't want to be any where near the crash zone.

Aviation is unforgiving of the lazy, ignorant and incompetent. If you're going to fly, this is critical knowledge. You need to commit it to memory. 

Reducing pitch is not a component of a stall, it's a component of the stall recovery. An uncommanded pitch down is often a symptom of a stall, but it is not necessarily a component of stalls in all airplanes in all configurations. . 

Critical angle of attack is not a component of a stall, but EXCEEDING  the critical angle of attack is a component of all stalls. 

Insufficient airspeed is also a component of all stalls. Just remember that this does not necessarily mean low airspeed. Increased g-loading and uncoordinated flight can lead to stalls at higher airspeeds 9i.e. accelerated stalls,

If you meant to ask the three components of a stall recovery - level the wings, pitch down and increase power.

Stall is a function of AOA

Reducing pitch is a cure, not a component of a stall.  Better would be low air speed.