If you don't rent a buggy or hire a driver you will stick to your resort or to Pipa's center, depending on where you're staying. So my advice is to rent a car (buggy is more fun and airy) and drive around to see the beaches, the landscapes, go to Natal, to Ponta de Cunhau, drive in the dunes, go south to the Sagi area, just don't stick to the resorts/inns.
Ask for it at you pousada or hotel's reception. They will arrange it for you.
First of all,you have to take a flight to the nearest big city,Natal.
All Brazilian airlines have flights to Natal
From the airport,you can rent a car,or take a taxi.
Taxis costs about 100 reais to Pipa.
Check out if the Inn you choose has transportation facilities from the airport to Pipa (many have).
If your option was to rent a car,take the freeway BR-101,pay attention to the signs for TIBAU DO SUL (about 70km),than turn left to Tibau,and than right following the signs to Pipa.It's an amzing way,through the coastline!!
I heard there are many options for those using a 4WD cars,but I'm not an expert about such roads!
Total distance from Natal's airport to Pipa will be about 90km.
You can also choose to take a bus,but not from the airport!!
If this will be your option,take a bus from the airport to the bus central station,and from there a bus ( the company name is TRANSUL) to Pipa.