I live in a suburb of Philadelphia and don't have a car to travel places. How can i get around to travel places otiside the philly area?

Most Philadelphia suburbs have SEPTA train stations, or a bus that will get you to a SEPTA station. You can get downtown easily on SEPTA. At 30th Street Station in Philadelphia, you can get on an Amtrak train to New York, Boston, Chicago, etc.

There's always car rentals.

There's a railroad. In one direction, there are a lot of trains that go to New Jersey and New York City, and a few that go all the way to Connecticut, Rhode Island, and Boston. In another direction, they go to Delaware, Maryland, and DC, and some continue even farther, to Virginia, the Carolinas, or even Florida. In another direction, they go west to Lancaster, Harrisburg, etc.

You can take a bus. Depending on where you're going you can take the train. You can rent a car.