Did you know that by default your engagement programs are turned on?
So,what does this mean?
It could mean that while you are setting this up if you have someone who qualifies with your criteria, this person or group of people could start receiving your email nurtures even before you are fully sure of having your program ready.
My recommendation is to turn it off the second you create the program and turn it back on when you are ready to push it live.
How to tun it off?
Go to your program Setup and change Program Status to Off. Once you are ready to activate it just change this setting.
This is a basic functionality of Engagment Programs but worth sharing for Marketo or Engagement Program beginners.