Career path in SAP SD or MM

Hi,

I currently work for Coca Cola Enterprises in the Distribution Department as a Operations Coordinator  for 12 yrs. I want to start a career in SAP Functional . The looked up which modules would suit my career path considering my work experience, SAP SD and SAP MM seemed to be the ones.

I am abit  confused which module to train on because they both cover bits of my role.

Please advise.

Thanks