how does waxing work?

Say I get myself waxed for the first time, Then I'm hair free for like 3 weeks right? Then do I have to let it grow out again before I can get another wax?
How do people deal with the growing back part until they can get it waxed again? What if u need to be hairless down there cuz ull be in a tiny bikini but aren't hairless cuz ur leaving enough length to get another wax? Or what if u wanna hook up with someone and be hairless but gotta grow it out till next wax.