There are various theories to lift but yes, the most commonly accepted theory is the camber of the wing increases the speed over the top of the wing surface creating low pressure (suction if you like) whilst the slower speed of the air under the wing is at a relatively high pressure. The difference between them creates lift.
As you rotate the aircraft, and therefore increase the angle of attack (the angle between the chord line [line linking the leading edge to the trailing edge of the wing] and the relative airflow over the wing) the upwash ahead of the wing increases, air is sped up even more over the top of the wing, the pressure is even lower and therefore the differential is even greater so higher angles of attack (effectively high pitch angles) give higher lift.
The components of lift are Lift = 1/2 air density x velocity squared x coefficient of lift x surface area
Probably a little above PPL level but a bit of background info never hurts.
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