When did you start sleep training?

Da

My DS is 2 weeks old and we’ve been having a hard time when it comes to sleep. He originally would only sleep on my chest and would cry the moment I put him down. Now he will sleep in the rock and play, and yesterday he took 2 four hour naps! The bad news is they were during the day so he was up and fussy all night. How do I switch it so he sleeps during the night and up during the day,