When you have network connectivity, tap the Options button, and click "Download Cell4 Data". Wait for that to complete. You can restart the game or start walking again and it should draw tiles.
1 is a surprise. If your device has GPS, and you granted permissions to the app to use location, it should move when you do. You also need to have the screen on while walking, because Android doesn't let most apps get location info and run in the background.
