Thanks for submitting your question!
Before starting CPR you should gently tap the child on the back. If there's no response whatsoever and the infant isn't breathing normally or at all, place the infant on their back and begin CPR. Apply 30 gentle compressions at the rate of ~110/minute. Use two fingers in the center of the chest just below the nipples.
Hope I helped, if you've got any further questions reply to my answer! :)
