You do not provide a very exact description of your problem.
I have Googled for the term "SHP file" and found several different meanings.
Apparently it is a file format for geographical data (maps).
QuickGraph does not support such a file format.
It does contain a shortest path algorithm that may be useful to you.
You'd have to write code to import an SHP file.
What makes you think using QuickGraph is a good approach to your problem?