Here's a breakdown:
* Bon jornais is a greeting, but it's not a standard French expression. It seems like a misspelling of "Bon Jour" or "Bonjour," which means "Good Day" or "Good Morning."
* pourle is a misspelling of "pour le."
* jour de Bastille is the French name for Bastille Day.
Therefore, the intended phrase is "Bonjour pour le jour de Bastille," which translates to "Good morning for Bastille Day!" However, the most common and natural English greeting for Bastille Day is simply "Happy Bastille Day!"