void loop(){
if (gpsSerial.available())
Serial.write(gpsSerial.read());
}
That will show you if you are receiving characters from the GPS properly. Work on that until you receive clear messages from the GPS. Then make sure your messages contain Latitude and Longitude: They won't until the GPS has a position lock. THEN you can use the TinyGPS library to extract data from the messages,
GPS doesn't work well indoors, although sometimes you can get a position if the device is near a window. Other obstructions - trees, nearby buildings etc can interfere with the GPS' ability to receive signals from the satellites.
In such situations, where the GPS cannot "see" sufficient satellites, it cannot figure out its position, which apparently is what you're finding with yours. Try taking it outside; even then it may take a few minutes to get a lock.