Basically lift from a conventional wing is created in a mixture of two ways:-

1/ Air is deflected downwards, due to the angle of the wing (the angle is known as incidence), and as Newton said, every force has an equal and opposite force, so the wing creates lift.

2/ More importantly, as the top of the wing is curved, and the bottom isn't (usually) the air has to travel a greater distance over the top of the wing compared to the bottom. Since this happens at the same time, the air over the top has to travel faster.

Any fluid traveling faster does so at a lower pressure (put very simply, due to something called conservation of energy; the energy of the extra speed coming from the pressure energy thus reducing the pressure). As there is a greater pressure under the wing, compared with over the wing, lift is created.

Actually, it's a lot more complicated than that, but those are the basics.

Hope that helps!

David C.