First thing, welcome to the community.
Second, there is no such thing as a blue nose pit bull. This is a name made up by back yard breeders to peddle dogs. Blue dogs are typically Am Staff or Am Bully, but not American Pit Bull Terrier.
Third, unfortunately there is no way to tell a dogs breed by looks. Especially mixed breed dogs, and most certainly mixed bull breeds. Due to media sensationalism, everything is a "pitbull"
While I do see the Shar Pei in your pup (they have a very distinctive look), the rest could be anything.