If a goy converts to Judaism on Sunday, Monday, or Tuesday, shall he recite Havdalah, since it is possible to recite Havdalah until sunset on Tuesday, or shall he not recite it, since he was not obligated to keep (the previous) Shabbos?
Also, if he converts at a time when it is no longer possible to recite the morning prayers, may he eat (even though it is forbidden to eat prior to praying the morning prayers, but here he was not obligated to pray, and now it is no longer possible for him to pray)? And even if he did pray before his conversion, he did so as a non-Jew, which has no halachic validity?
If he didn’t have shabbos, and it is as if he was born today, of course he doesn’t make havdalah.
I would say that since he still has the obligation to daven, although shacharis is no longer applicable, and he should say birkas hatorah of any other bracha that is a blessing, prayer and blessing, and then he can eat.