So I’m currently a sophomore in high school, so I still have plenty of time to think about this. Yet, I would still appreciate any advice and/or knowledge beforehand. I’m planning on studying in the medical area, or business management. The college options I’ve selected are Truman State University, Ohio State University, and Seoul National University. I currently live near Truman in MO. I’m still if I want to study all the way in South Korea also. I plan on studying 8 years of college at most. So if anyone has any pros/cons, advice, recommendations, or anything that would help, I would appreciate it a lot 
Your question is premature because you don’t have a definite GPA nor do you have test scores.
You will need to build a list with two affordable safeties, a few matches (where your scores place you above the average to near the 75% mark), then add dream schools. Truman State may be your safety, or it may be your match, or it may be a reach. It’s all relative to your current achievement.
You can calculate your EFC. If it’s low, look up “meet need colleges”.
Going to South Korea would involve military service - How well do you speak, read, write Korean and understand the culture? Have you stayed there for a certain length of time.
Yes, you have lots of time. The most important thing for you now is to learn yourself–what do you enjoy, what do you want to learn, how do you like to spend your time, what makes you your best person, who makes you your best person. Typically, people your age naturally focus more on what is important to them and less on what others think important. It seems like you are already self-reflective, which is great.
In regard to college,
The first thing is, what schools will be financially feasible? Schools are often very expensive. Merit and financial aid are often available, but securing it can be a complex process, with some uncertainty. For example, I have a great application and think a terrific school like Denison is a safety/match for me. But I can pay $30k a year. It cost a lot more. Will I get enough aid? Maybe all of them are affordable for you. Maybe some, maybe not others. Maybe that will be a huge consideration.
Then start to think about the places that will be financially possible and good fits for YOU? For example, US v. international school? Large public university v. small LAC? Urban school v. small city school v. college town v. more rural school? What kind of culture fits you? Religious? Conservative? Activist, progressive? STEM school? Party? Big-time sports? Some combination? No need to answer now. But maybe things to start thinking about in terms of what works for you. Maybe visit a few schools, even local ones, of different types.
Then you can start to narrow things down. For example, you like big state schools. OOS schools, or most, are too expensive, so you look at those in your state, and maybe a few that do give aid to OOS students. Or, you would like the smaller communities and smaller classes of an LAC. Which ones work financially (give merit/financial aid) and academically (would you be looking at ones that are test optional).
So start thinking about what you like and what works financially, then try to find places and programs that fit. No need to decide now. You are growing as a person, so it would be natural and normal for you to change your mind, maybe several times, over the next few years. Good luck!