Greece has many islands so many people get around by using "water taxis". Many islands ar very small and don't allow cars do to space, so people also use Vespas and other small vechicles.
The geography affected Ancient Greece because the climate and bumpy hills changed the agriculture. It would be harder to grow many crops in the hills where farmers worked.
The mountains helped develop the city-states by separating them. The bays provided harbors for ships, and the coast was fertile, so the could farm. They used the seas for trade and transportation....