The most appropriate steps Luka would likely follow to create a wheel and axle prototype with cardboard and a drinking straw would be:
First, he cut a circle out of the cardboard. Then, he cut a small circle in the center of the circle. Finally, he put the drinking straw through the small hole.
This method effectively utilizes the two main components of a wheel and axle system, where the circular cardboard pieces represent the wheels, and the drinking straw acts as the axle.