Paros can be easily reached from Piraeus, where there are daily ferries going to the Cycladic islands. The journey takes three hours or more depending on the speed of the boat you take and the schedule it follows.
Sometimes there are ferries from Rafina to the island of Paros. On the airport of Athens there are regulair busses going to Rafina, and you don't have to drive through Athens itself. Off course you can also take a taxi. The ride takes about half an hour. It's also possible to fly to the island of Paros from Athens.
If you want to check the ferries from and to Paros and order a ticket - .
Paros has an airport for for domestic flights and can also be reached by plane from Athens (national flights only because there is no international airport). For plane tickets from Athens to the island of Paros check .
When you visit Paros it is a good plan to rent a a car, because if you don't you are missing out on a lot. The island has a lot of things to offer and it is a good plan to go and explore it.
Compare prices of the different car rentals and different kinds of cars with reviews of the car rental company on the website of rentalcars.com - .