In Xcode 6 how do you develop an App that gets the user's core location?

I want to develop an App that first you press Start then you walk with your iPhone then press Stop and it should find out how much you walked using GPS and then comparing the two locations at when you pressed Start and Stop.

I want to know first is this possible and how would you get the latitude and the longitude of the user (also known as the core location)?

Thanks in advance, BTW if this isn't the right community please tell me (w/ link) where to go and post this.