Plan to get a solid education. Horses are a hard life, and it can literally break your body, you need your mind to be able to back you up. Additionally, you can set yourself apart from other horse professionals by having a solid background in business, or finances, or something like that. Being able to teach riding is one thing, but an education will teach you to run your own business.
Other than that - get working student positions, and ride everything. Ask questions about everything. Seek knowledge from every source, take every lesson, read every book. Plan to spend your summers, vacations, and time after school at a barn.
Learn as much as you can from as many people as possible. When training and teaching I take things from all sorts of riders. From reiners to dressage to jumpers; they all have important info.
Most will tell you not to make horses your career. My advice on that? Have a back up plan. I have a bachelors as well *just in case*