Joining the British Military as a Veterinary Technician?!?

I'm a sixteen year old female just coming to the end of my last year at high school. Becoming a Military Veterinary Technician has been my dream since being in year nine. (before that I wanted to become a zoologist). I would love to know what A-levels I would need if any? Would I be better off going to College or an Army College in either Harrogate or Winchester? Would I be better off going to College at all? Do I need to be a qualified Veterinary Technician before enrolling up to the Army then proceeding to basic training or do you learn to become a qualified Veterinary Technician after training? Basically I need to know where to go after high school and what qualifications I would need? Also as a bonus question can you enroll up to the Army then drop out for a bit whilst you go to University and then re-join when you have a degree? Would I be better off signing up to be Territorial rather than Regular? With answering these questions it will really help me as I can not go to my nearest Army Careers Advisor until I need to ring them after applying because my mother detests the idea.