Getting to Paros
There are two ways to reach Paros. The first one is by plane and the second by boat.
Paros has a national airport that receives flights from the main international airport in Athens. Domestic flights from Athens international airport to Paros are serviced by the Aegean airlines. Planes that fly to Paros have small passenger capacities and since demand is high on peak periods (mid July-end of August) make sure you plan in advance. If traveling from abroad, arranging such a flight connection with Paros it will be the fastest way to arrive on the island.
By Ferry Boat
Boats to Paros depart either from Piraeus port or from Rafina port. Piraeus offers more itineraries than Rafina and there are various types of boats doing the trip, slower ones that are cheaper
4.5 hrs travel time, around 32euro/person
Blue star ferries
and faster ones that are more expensive
3 hrs travel time, around 45 euro/person
These ferry companies service both from Piraeus and Rafina ports.
Regarding the transport to Piraeus port from Athens airport there's a frequent bus line that departs from the arrivals terminal, tickets and info on the spot
5euro/person, around 1hr travel time
Buses to Rafina port are serviced by Athens domestic bus lines
Bus to Rafina port
Taking a Taxi from the airport to the port is also an option and these are easily found outside the arrivals section.