[cmos]

We just started putting our kids on the potty around 5 months old.. they liked to sit on it and we would read to them. Sometimes stuff came out. But more importantly it was part of our routine before and after naps, and so by 1.5-2 they were fully trained mostly by themselves.

Waiting too long can create issues with sitting on a seat with a hole in it - at least make that a common thing you do.