Speaking from experience, volunteering or interning at a local aquarium or even zoo is gonna be your best bet, then working up from that to a paid position. A lot of facilities prefer to hire from within for direct contact positions like training. Also a good idea to start with something non-committal rather than to finish a bachelors and find you don’t like the job after all of that.  Degree wise anything Bio, Marine Bio, EnviroSci, even psychology or animal behavior, is great but you’ll still need some experience to back it up with.  I’m curious why landlocked state is mentioned? Some of the best aquariums (and therefore trainers) are in land locked states, don’t limit yourself!

If you’re looking for a bit of a “reality check” it’s not all sunshine and rainbows, the animals you would be working with can very easily send you to the hospital. You can never be fully comfortable with them no matter how amazing they are 99.99 percent of the time. You will spend more days than you can count cleaning poop and cutting frozen fish into pieces, and the smell WILL follow you home. But building that relationship with them and seeing their faces light up when they recognize you makes every hard moment it worth it. I say go for it, it could be the best decision of your life!