About Playgroup

hello, I am the new mom. So I need your advise for the school info.

My baby is just 2 months old. I heard that it is time (or already too late ) to find the playgroup for him.. Could I know normally how old he should go to playgroup?
I live in Admiralty, could u recommend any good school?

We would like to apply Australian International school or GSIS when he enters kindergarten few years later, so which school for playgroup may bring him higher chance to get into these 2 schools? Thanks