Is it possible to retrieve my IPhoto libraries? I just bought a macbook pro running IOS 10.11.3

Retrieve from where? If you had and older Mac running iPhoto and want to use that library with Photos on the new Mac, you can copy the iPhoto Library from the old Mac to the new one and then migrate it to the new Photos app: Get started with Photos for OS X - Apple Support

The following also may be of interest: Move your content to a new Mac - Apple Support