How do I go about this?

I really want to start a animal rescue/shelter. I’ve noticed that there is a huge need for this all over the world and have always wanted to work with animals but didn’t feel like being a veterinarian was for me so I’m currently in nursing but the tiny voice telling me to go into animal rescue has become a very big and loud voice. I know this could take years to start which is fine. I’d also like for this to be something I did full time if that’s possible. Does anyone know how I should go about this?