Hi!
I'm from the Philly suburbs so I can offer a few recommendations. I'm not sure what kinds of things you are looking for BUT here are some ideas:
-Philadelphia Museum of Art (make the Rocky run too if you want)
-South Street (Tons of cool little shops and things)
-Definately hit up Genos or Pats for a Cheesesteak
-Walk Kelly Drive and see Boathouse Row
-The Franklin Institute is a personal fave and they are having an exhibition right now that is apparently of human cadavers (Sounds sick but interesting)
-For the touristy stuff: Liberty Bell, Constitution Center, Betsy Ross House etc.
-If you want to venture out of the City you can hit up Valley Forge National Park & The King of Prussia Mall
Hope you have fun in the City of Brotherly Love!