From back in my childhood when there wasn’t such a distinction - my gut says it was probably a “tweenish” book back then. I was born in 1980, and I’m guessing I’d have read it around 1990 or so.
I could go ask the children’s librarians downstairs but one of you probably knows right off the top of your heads.
Young male protagonist in a culture which prizes hang gliders as a means of… transportation/hunting? I’m pretty sure it’s one of those “make your own hang glider as a rite of passage and paint it all culturally significantly” sort of things. Separated from a more warlike culture by a desert nobody crosses, but of course our young man crosses it. (He may have been exiled.) His end of the continent is mountainous, which obviously helps out with the hang gliding thing, while the other isn’t. They have these big fast war-lizards, I think, and he eventually learns to get his hang glider up in the air with the lizards giving him a boost, like flying a kite.
Could it have been a comic book? Your summary sounds a bit like Nausicaa of the Valley of the Wind. The protagonist is a girl, but it has a personal flying machine for the heroine, deserts, conflict between warlike and more peaceful cultures, and some fantasy-ish creatures who are descended from modern creatures who were mutated due either to climate change or intentional genetic engineering projects. People ride flightless birds like horses, and there are giant house-sized insects.