Tap the GPS icon to find your location on the map. Your location is displayed as a blue dot. The blue transparent circle is an indication of the accuracy of the GPS fix (the smaller the circle, the more accurate of a fix). If you're not physically within the extents of the map, "Not on map" will be displayed where the map coordinates are.
On devices with built-in GPS, your location will be triangulated within a few seconds. Depending on your device and available services, your location is determined using a combination of cellular, Wi-Fi, Bluetooth, and GPS. Learn more about location access in Android here.
Avenza Maps has two different compass options when viewing a map. Follow-mode, and Compass-mode. When the compass is enabled, as shown above, the default is Follow-mode (map is in the default orientation, and the crosshair will follow your movement). If you tap the GPS compass again, it will change to Compass-mode (symbol will change as well), and the map will rotate based on the direction you are facing (see image below). A compass also appears in the top-right of the map view. If you tap the compass a third time the compass will be disabled. You can also rotate the map manually using a two-finger rotate gesture.
Your mobile device uses various sensors to obtain compass directions. These sensors are prone to interference and thus you may need to calibrate your device compass from time to time. If you are having issues with the Avenza Maps compass, please consult your device manufacturer's instructions on how to calibrate your device compass. After recalibration is complete, if you are still having issues with the compass, please ensure that you are clear from any potential satellite disruptions (e.g. tall buildings, dense tree cover, etc.) as these will also interfere with a signal.