Edit:
OK, I figured it out. You have to interact with discobot in a PM.
I was looking at the badges and noticed the Certified one. How do you get the certified badge? Where is the “New user tutorial”. I came across this ,but doesn’t help much. It shows two different tutorial badges. I tried sending discobot a PM ,but that didn’t do much of anything.
Badges are updated a few times a day - I just checked and you have it now 
I am trying to earn this certified badge but don’t understand the process
To get the certified badge you need to complete all steps of the Discobot onboarding tutorial.
Where do I find such tutorial
Just reply to the private message Discobot sent you when you signed up and follow the instructions.