The big thing is make sure your math is strong. Stronger than what's required even for some forms of engineering. A met major is one of the most math intensive majors out there. I hope you're already taking pre-calc this year so you can talk AP calc your senior year. And I hope you have teachers in those classes who are better able to break things down than mine was. I essentially taught myself Calc my senior year because, while my teacher was one of the smartest people I've ever met, he was not good at breaking down concepts. Once you get to college, your advisor will be able to point you in the right direction as far as classes that you need to take.
If possible, I would try to knock out gen ed and prerequisites at a community college. It'll cost you a fraction of the money and they credits will count the same. Transfer to a 4 year school for your junior and senior years and go from there. My other recommendation is to stay in state if at all possibly for the same reasons I outlined above. There are plenty of mets out there that graduated from schools *other* than Oklahoma, Iowa State, Mississippi State, etc. I know there are a fair number of NWS mets who graduated from IU, for example. With you being in Indiana, if you're able to knock out some of the early stuff at Ivy Tech, then transfer into IU or Ball State, that would save you a ton of money over the long haul and have you in a lot less debt after graduation. IU is definitely less expensive than Purdue and Valpo. Ball State may be less expensive than IU. I'm not sure on that. And I believe Ball State has a Met program as well.
With all that said, I would also temper expectations. While it's certainly possible to get into that segment of the field, meteorology in general is highly competitive. There are far more grads with met degrees than there are met jobs across all sectors. That was true even when I graduated high school nearly two decades ago, and that's a big reason why I decided not pursue that degree path. So with that in mind, networking is key. To be fair, regardless of career field, networking is key. One thing I learned while serving in the Army was to always take advantage of opportunities to meet people in your field (or intended field). Building those relationships as you finish HS and get into college will give you a greater chance of landing a job where you want once you graduate. It's no guarantee by any stretch, but it certainly helps the odds some.
There are also other fields that, for lack of a better term, organizations like NWS/SPC need in order to run. You may find that something like IT may be your ticket in, particularly if you're not as strong in math, but are good with computers and networks. If you get to a point where you realize you can't hang with the meteorology course work, maybe something like IT or GIS will be a way to get your foot in the door.
I know that's a lot to take in, and I'm not a met myself as I mentioned. But a lot of that is advice that carries across several career fields.