The most common way to get to Kaprun is from Salzburg Airport, which is 98 km from the resort. You can rent a car at the airport and drive to your destination via the A10 and B311 in about an hour and a half. You can also take a cab, which will cost around 150-170 EUR.
Another question is how to get to Kaprun, by public transportation. The easiest way is to take a trolleybus from Salzburg airport to the train station. From there, there are trains to Zell am See. They stop in the city center, from which it is not far to the bus station. From here there are regular buses to Kaprun.