Yes, as others indicate, unless you are in the guaranteed admission thing for high school grads -- don't set your heart on a single school.
No matter how impressive your app, there are no absolute certainties in med school admissions.
That said, to build a competitive application:
If you want to maximize your chances [within reasonable expectations], keep above a 3.8 GPA, score 35+ on the MCAT (or whatever the new scaled score is when you apply), do the traditional volunteering, do research to acquire at least a couple pubs/posters, build some meaningful relationships over the years to render a few shining LOR's, and find some sort of unique X-factor that separates you from the other 500 applicants just as impressive on paper as above.
Likelihood is that, if you achieve all those things above, you will be competitive at all schools and your target will slowly shift to Hopkins/Harvard/etc.
Nevertheless, Pitt is a great school with a powerful rep and countless opportunities. Graduates go all over from Derm at MGH to Neurosurgery at UCLA to small community programs in Primary Care if that is your thing. The city is largely safe, entertaining, and extremely affordable. So, in that sense, you chose a good dream school.
Good luck.