Do you want to send the raw NMEA characters (not recommended), or do you want to send a few of the parsed GPS values (much more efficient)?
If you need to parse the GPS information, consider my NeoGPS library. It's smaller, faster, more reliable and more accurate than all other GPS libraries, and the examples are properly structured. It's available from the Arduino IDE Library Manager, under the menu Sketch -> Include Library -> Manage Libraries. Even if you don't use it, there is lots of information on the Installation and Troubleshooting pages.
Be sure to read the section on Choosing a Serial Port. It can save you lots of headaches later.