Can't really add much to
MechEngr's perfect explanation, except a couple of polishing details.
1) Most aircraft wings are installed with a slight positive "angle of incidence." That is, the line between the wing trailing edge and leading edge points slightly "up" relative to the fuselage centerline (or cabin floor), maybe 1-2 degrees. So that the floor can be level for pax in cruise, even when the wing has a
positive angle of attack (and probably other reasons.) Exception might be for aerobatic aircraft, where the aircraft may often be flying upside down, and thus symmetry up or down is desirable.
2) In a "slow-motion" version of the level-plate analogy, on final approach down a 3° ILS glide slope - at approach speed - the aircraft attitude is usually slightly nose-up (2-4°). For additional lift at the slower speed, and to make sure the stronger main landing gear touch down first. While the descent path through the air is ideally 3° down. For a
net AoA of 5-7° (plus any built-in angle of incidence).
Concorde, of course, had, and needed, an even higher approach attitude/pitch (10° plus), With a landing AoA even higher, thus the need for the drooping nose, so that the crew could still see the runway ahead.
https://upload.wikimedia.org/wikiped...Fitzgerald.jpg