How should one go about starting in aesthetic nursing field?

If you are talking about Laser Hair removal, Botox, etc? You can take an online laser safety course as places that do this need a person to meet state requirements. If you are an RN you can get you RNFA and work with a Board Certified Plastic Surgeon in surgery at hospitals or no RNFA and work with them in the office.

There are courses for nurse anesthetists. You get your CRNA and apply for Jos, usually where you train.