Welcome @Learner
Create a ringed-fence similar to the example described here Location sensor (ringed fence / circular ringed fence) .
Alternatively, calculate the distance from your current location constantly (perhaps using a Clock); when the distance is small (perhaps 10 meters or so) you determine you have arrived. There are several way to calculate distance between two points; use a Blocks algorithm or use the built-in method in the Maps/MapMarker components. These methods are described here>Calculer la distance entre son domicile et un point donnée dans une textbox .
If you check your CurrentAddress to exactly match a coded address (in a Text box or in a List selected from a ListPicker) your app will almost certainly never warn you that you have arrived because the two 'addresses' will almost never match exactly.
Read about Accuracy in * Using the Location Sensor . The tutorials explain why it is nearly impossible to determine whether a CurrentAddress matches an actual street address with any reliability.
Read about CurrentAddress HOW TO: Parse a LocationSensor's Current Address by SteveJG
Regards,
Steve