Holistic nursing is many things. The way I started to understand this concept was to understand Maslow's Hierachy. When you care for people as a nurse, you meet the basic needs first and THEN you can address higher needs. This includes spirituality, love, emotions, what the person needs beyond physical.
A holistic nurse doesn't need a certificate to be caring. Research nursing theorist Jean Watson and her 10 carative factors. If you want to be holistic, try to attend a nursing school
with a holistic focused nursing theorist model (all schools
have a theorist they chose for the focus of their teaching).
Nurses take care of people, doctors take care of peoples illness. Holistic nurses understand it is more than a lasix drip for congestive heart failure, or a medication to reduce cholesterol. It is forming a trusting relationship so the client (usually you take care of very short term) can share his REAL needs. Sometimes you will be the only person they will be able to talk to about the REAL issues, and therefor, have holistic healing.