This is really simple. Find the best teacher you can who is a member of an accredited post-secondary institution and go to that school. This teacher needs to have had visible success helping young people to sing better. This person will be your mentor for four years. They will be responsible for your vocal health and growth. They may also be your faculty advisor and you will be seeing a lot of each other in lessons, seminars, classes, juries, and maybe even other places. Unlike biology, or business, or economics, do not go for the name of the school. The name of the school doesn’t matter at all if you don’t learn how to sing. If you come out of undergrad with a good technique, then you can start thinking about resume-building with grad school and young artist programs. If you don’t learn how to sing superbly, you are wasting your education. You won’t learn how to sing just by being enrolled in a “good school” with a teacher who doesn’t work for you.