Android - Getting Location Services to Work

Question

I've tried using both FusedLocationAPI and Location Services to try getting location information and with both methods, I'm not seeing the Listener / Callback function run. I've been following Google's tutorial. Here is my (terrible) code. Any thoughts?

final LocationRequest locationRequest = LocationRequest.create();
locationRequest.setInterval(10000);
locationRequest.setFastestInterval(5000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
        .addLocationRequest(locationRequest);
SettingsClient client = LocationServices.getSettingsClient(this);
Task<LocationSettingsResponse> task = client.checkLocationSettings(builder.build());
task.addOnSuccessListener(this, new OnSuccessListener<LocationSettingsResponse>() {
    @Override
    public void onSuccess(LocationSettingsResponse locationSettingsResponse) {
    }
});
task.addOnFailureListener(this, new OnFailureListener() {
    @Override
    public void onFailure(@NonNull Exception e) {
        if (e instanceof ResolvableApiException) {
            try {
                ResolvableApiException resolvable = (ResolvableApiException) e;
                resolvable.startResolutionForResult(MainActivity.this, 1);
            } catch (IntentSender.SendIntentException sendEx){
                // Ignore the error
            }
        }
    }
});
locationCallback = new LocationCallback() {
    @Override
    public void onLocationResult(LocationResult locationResult) {
        if (locationResult == null) {
            return;
        }
        for (Location location : locationResult.getLocations()) {
            lat = location.getLatitude();
            lon = location.getLongitude();
        }
    }
};

fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
fusedLocationProviderClient.getLastLocation()
        .addOnFailureListener(this, new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                //do something
            }
        })
        .addOnSuccessListener(this, new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                if (location != null){
                    lat = location.getLatitude();
                    lon = location.getLongitude();
                }
            }
        });
fusedLocationProviderClient.requestLocationUpdates(locationRequest, locationCallback, Looper.getMainLooper());