I do not know about infant CPR. But I would never trust myself administering CPR to even an adult, after watching something online.
I have had regular first responder refresher courses at work every two years - and i have to say: I always relearned something every two years, because not having done it (luckily no-one needed my first aid) meant I had forgotten quite a bit in those two years.
Especially how it feels to administer CPR. and how to position the person.
So not sure where you are located, but in Germany, you can volunteer to become a first aid responder for your company - they love that, because from a certain size on they must have enough of us. And you get a certificate every time you retrain (you need to do this regularly every two years, as said).
We even once hat a baby puppet for training, but I was not able to test it that time (as it was not mandatory, I wanted that the parents actually had the chance - or those planning for kids).
The hospital we had our kids at had a baby CPR class and an expectant parent class. The CPR class didn’t give you a certification but you learned what to do for CPR and choking.
