I am very interested in biology and medicine but I also really love physics and calculus. I’ll be a senior in high school this year and I know that I want to be an engineer and I’m hoping to go to Georgia Tech but I don’t know which field I’m most interested in. I would love to do drug design and research which I know falls under chemical engineering but I don’t know if I’ll be able to handle the chemistry courses I’ll have to take. I really love physics; if I could turn everything into a physics problem, I would. I love the real world applications of physics. I know civil and mechanical engineering have a lot of physics, but what else do they do? Biology is extremely interesting to me as well; I took Microbiology at my school last year and learning about bacteria and viruses and their structures intrigued me, and so does the anatomy and function of organs, organelles, and molecules like proteins. Anatomy and biochemistry are interesting to me. And I’ve always loved math. Differential and integral calculus were a breeze for me. I love solving problems. So based on my interests, what does it sound like I’d be interested in?
You don’t need to know what you want to major in going into college. Most places allow you to try things out your first year and then pick a major your second year.
You could look in to Biomed engineering but be prepared to continue on and get Masters in that field if it interests you.
Some schools do offer an intro type class that goes over the various areas of engineering. The first year, all engineering students tend to take/need the same Calculus/Physics/Chem classes so you have time even if you did not choose right away.
@wanderlust9871 I’m in the exact same position as you. I’d like to have some advice as well 
However, many popular state flagships have competitive admission to engineering majors for students who are already enrolled. Michigan is somewhat unusual among popular state flagships in that students in the engineering division can declare engineering majors with just a 2.0 GPA and C grades in prerequisite courses. Many other popular state flagships (or engineering flagships) like Minnesota, Wisconsin, Penn State, Purdue, Washington, Virginia Tech, Texas A&M require significantly higher grades or GPA to enter engineering majors, even for students admitted to first year pre-engineering status (some do admit some frosh directly to the major). Some other popular state flagships like Illinois, Texas, UCs admit all or most frosh directly to specific engineering majors, but changing major after enrolling may be difficult, due to each major’s capacity already being filled up with frosh direct admits.