will you give me a ride back to the terminal when I return my car?

Use Airtrain > its free, no need for ride back.

There are also buses that go directly to the terminals

AirTrain is only 5 minutes away you can walk right up the stairs and it take you right to the airport to the terminal

You will need to take the Airtrain from the Hertz rental station to the terminal..just a 5 min ride