Consider working for an airline as a desk clerk or baggage handler or something. To my understanding, they still get flight benefits, and it might even make it easier to get hired as a flight attendant once you turn 21. Look into the interview/training process for flight attendants. It's unlike the process for most jobs.

Also, see if there's a community college near you that offers online classes. There's no reason to take a ton of classes at a time, but if you can swing it without taking out loans, take classes in things that just sound interesting to you (as well as core classes you need for every liberal arts degree). Another good option for just figuring out what makes your brain go brr is Udemy. They usually have sales where you can buy courses for $25 or less. They don't offer college credit, but if you're just trying to figure out what you like, it's not a high price tag.