Congratulations, hope you have a great time! I took an adult gap year, and it was one of the best decisions of my life.
Life in an American suburb is a series of goalposts. Every few years, a new school. Then you go to college, find yourself, and discover that a career is more of the same: every few years, a new promotion/job/grant.
When I realized that, I figured that my joints and back would be at least as ageist as my future employers, and quit. Having watched a lot of Top Gear in school, I bought a dirt bike, modified an old pickup into a mini-RV, and went on a tour of the US' forests and national parks.
It was incredible. Exploring such an enormous and diverse area presents you with a lot of new perspectives. Of course, it was a terrible financial decision which I couldn't really afford, but I'd do it again in a heartbeat.
As I enter my 30s and start to see my peers get seriously hurt by activities like skiing and climbing, I find myself scaling back my "see the whole world" ambitions. Maybe I played things too safe, but I'm definitely glad that I didn't stay in my rut.
Anyways, it's nice to have a chance to contemplate your place in life and society while you're still spry enough to shurg off a few falls. Even my grandmother took an ill-advised teens-20s road trip across the iron curtain. A good walkabout should be a basic human right.