"What is this lesson about?"
Translation:O czym jest ta lekcja?
When "o" means "about" (so mostly), it takes Locative. Ta lekcja jest o poezji. (This lesson is about poetry).
It is impossible. This is the most unbreakable rule of Polish word order.
it is always preposition+ (words describing noun/pronoun)+ noun/pronoun
Even poets don't break this rule.