You can download an app like Backcountry Navigator or go to the following link (and save it in your phones bookmarks) http://yourlo.ca/tion/?md=locate.md on your phone to get the lat/long off your device.

Navigation

To learn more about what latitude and longitude is, and how to use it, check out this link to the manual for the introductory SAR program that all SAR volunteers take. The info on Lat/Long starts at page 5-16. The map and compass sections are Well worth a read.