You do not need any formal training to use a defibrillator, the device will guide the user through each action they need to take using audio and visual instructions. It is however important to note that statistics show that:

Only 40% of bystanders who witness a cardiac arrest will intervene and offer CPR or defibrillation. Survival rates significantly increase if a bystander has received training and spontaneously provides CPR and defibrillation.

We would therefore strongly suggest that awareness sessions are provided as a minimum but that CPR and defibrillation training significantly increases the likelihood of the equipment being used to save a life.