Depending on the bus line, the bus stops on a mountain or visitor parking lot. There is, among other things, a viewing platform.
It is possible for 200 yen (one way) or 300 yen (round trip) to climb into a lift (quasi ski lift) and dive directly into the dune landscape.
Alternatively, you can also walk to the dunes, as only one street has to be crossed.
The lift is a bit further away from the train station, so it is better to travel by bike or by bus. For cars there is parking, with some fees.