Did Bella and Edward ever leave forks?

Yes, in New Moon, Edward left Bella and left Forks completely. Bella, Edward and Alice are in Italy at the end of the book too. Also in Twilight, Bella and the Cullen family go to Phoenix.

In Breaking Dawn - Bella and Edward's honeymoon is out of Forks too at and island called Isle Esme.

If you are wondering if they ever leave after the forth book, that is up to your imagination. You can imagine them staying at the Cullens' permanent resident in Forks but you also have to take into consideration that Carlisle is not aging and he has to look older the longer he stays as a doctor in Forks. I would belive that, after a decade or so, Edward and Bella would move onto different places--perhaps college.