If you can without impairing your grades or progress toward a degree, get a part time job and start saving money. Unless your parents magically decide to foot the bill for everything, then you are going to have to do this on your own money. And even if your health insurance covers therapy, hormones and gender confirmation surgery, gender transition is still very expensive. Just being a girl is expensive in terms of clothing, shoes, makeup, jewelry and accessories (like handbags). If you need face feminization surgery, voice feminization surgery, breast augmentation or body contouring, then things are going to get really expensive.
I know one transitioner who added up the cost of everything. Even though she had health insurance, she spent over $100,000.00.
Because you are young, you may not need any surgery— but even if you don't and have good health insurance, this is still the kind of thing where every time you turn around, you need to spend $100 or $300 to pay for something. The time to prepare for that is now.