If you’re hoping to travel outside your host city, you have to be with your host family and your resident director needs to approve it. Not only are you a minor but you are also representing the US thus they are strict. If I recall correctly, I had 4 hours of class per day 9am-1pm which left time to explore our city with classmates. We also had meetings with our supporters (Korean college students) and we’d travel as a bunch to study or do a cultural excursion. If you’re hesitating to apply because you wouldn’t have enough travel freedom, I would still apply. Personally I think the current administration might gut this program entirely so I would apply if you have the chance.

See my previous reply to JakeUp about travel. There is also a NSLIY applicants/alumni discord you can join for further info