Which medical training program would be best to take to become a cancer registrar in the future?

I am currently a stay at home mom of three children, waiting for my youngest (2 1/2 years old) to start school and then I am going back to school with the dreams of becoming a cancer registrar.

There is a training center in my area that offers 30-38 week courses (depending on major) and its FREE. Finding out about this place is like my dad opening a door for me to help find a cure for the cancer that quickly and tragically took his life.

There are 3 majors they offer in the medical field and I am not sure which one is best suited for what I want to do. They are:

*Medical*

eMA: Electronic Record Medical Assistant

Medical Claims Processor

Medical Coder

I do understand I will need more education than this alone, but this will get me ready for what I need afterwards.

I would greatly appreciate words of advice on where to start. Thank you.