How to convert lat lng to a Location variable?

You have to instantiate Location, before accessing its members. For example

Java

Location temp = new Location(LocationManager.GPS_PROVIDER);
temp.setLatitude(23.5678);
temp.setLongitude(34.456);
float distance = location.distanceTo(temp);

Kotlin

val distance = location.distanceTo(Location(LocationManager.GPS_PROVIDER).apply {
    latitude = 23.5678
    longitude = 34.456
})

Alternatively, you can get the distance without instantiating a Location object at all using the static method Location.distanceBetween().

float[] results = new float[1];
Location.distanceBetween(1, 2, 2 , 2, results);

public static void distanceBetween (double startLatitude, double startLongitude, double endLatitude, double endLongitude, float[] results)

The computed distance is stored in results[0]. If results has length 2 or greater, the initial bearing is stored in results1. If results has length 3 or greater, the final bearing is stored in results[2].

Parameters

startLatitude the starting latitude

startLongitude the starting longitude

endLatitude the ending latitude

endLongitude the ending longitude

results an array of floats to hold the results