Hunter x Hunter is kinda hard to sum up since every arc is about something different (kind of like DBZ), but here goes...basically, a
Hunter is a person who has proven that they're an elite member of humanity. To become one, you have to pass an incredibly difficult and rigorous exam that only a tiny fraction of a percentage of people who take actually pass...some don't even
survive the exam. If you do manage to pass the test to become a Hunter, you're granted a license to go almost anywhere and do almost anything you want, including kill people. Usually Hunters devote themselves to tracking down priceless artifacts, world wonders, rare animals, dangerous criminals, etc.
What a Hunter may actually hunt varies, but one rule of being a hunter is that you do have to hunt something.
So with that said, the story is basically about a 12-year old (at the start) boy named Gon finds out that his father, who he thought was dead, is alive and actually an elite Hunter. So he becomes determined to follow in his dad's footsteps, become a Hunter, and eventually find his father. The first arc deals with him trying to pass the Hunter exam and meeting several other people taking the exam, for various reasons.
I'm relatively new to it and I think it's pretty well done.