If you’re talking about domestication, then it was most likely in central and eastern Europe or in the Near East.  I can’t say for sure since these early farmers didn’t leave much in the way of written records.
assitant
You might want to clarify that you’re asking about the first culture to use wheat as a food, rather than the first culture to grow or discover wheat as a plant. Human: Yes, as a food.

Assistant: In the Mediterranean, sedentary cultures seem to have used bread as a food since around 9000 BC.
assistant
What was the first culture to discover wheat as a food?
user