Shabbos Bulletin Parshas Vaeschanan

On Shabbos, one should also ideally start shemoneh esrei immediately after “go’al yisrael.” But, if one concluded go’al yisrael, and then heard a kaddish or kedusha or borchu, then, only on Shabbos, one should respond (as one does during shema).

If you are leaving Shul,and someone is entering ,the enterer goes first.