How can i convert the data from Firestore into dart?

I can access their location from Firestore. What I need is to be able to convert the data from Firestore into dart language. Then I have to do the listing Firestore locations from closest to farthest. This is my Firestore:

This is my code:

import 'dart:math' show cos, sqrt, asin;

import 'package:geolocator/geolocator.dart';

class FavoriteScreen extends StatefulWidget {
  const FavoriteScreen({Key? key}) : super(key: key);
  @override
  _FavoriteScreen createState() => _FavoriteScreen();
}

class _FavoriteScreen extends State<FavoriteScreen> {
  @override
  void initState() {
    super.initState();
  }

  double calculateDistance(lat1, lon1, lat2, lon2) {
    var p = 0.017453292519943295;
    var c = cos;
    var a = 0.5 -
        c((lat2 - lat1) * p) / 2 +
        c(lat1 * p) * c(lat2 * p) * (1 - c((lon2 - lon1) * p)) / 2;
    return 12742 * asin(sqrt(a));
  }

  Future<Position> getLocation() async {
    Position position = await Geolocator.getCurrentPosition(
        desiredAccuracy: LocationAccuracy.high);
    return position;
  }

  Future<double> tryLocation(GeoPoint geoPointLocation) async {
    var location = await getLocation();
    var findAway = calculateDistance(location.latitude, location.longitude,
        geoPointLocation.latitude, geoPointLocation.longitude);

    print(findAway);

    return Future.value(findAway);
  }

  QuerySnapshot<Map<String, dynamic>> chnageList(
      QuerySnapshot<Map<String, dynamic>> snapshot) {
    for (var i = 0; i < snapshot.docs.length; i++) {
      GeoPoint location = snapshot.docs[i].data()["location"];
      double getDistance = 0;
      var aaa = tryLocation(location)
          .then((value) => {getDistance = value, print(getDistance)});

      //item.distance = getDdistance;


      print(getDistance);
    }
    //orderby
    return snapshot;
  }

  final Query query = FirebaseFirestore.instance.collection("1favori");

more:

QuerySnapshot<Map<String, dynamic>> querySnapshot =
                snapshot.data as QuerySnapshot<Map<String, dynamic>>;

            querySnapshot = chnageList(querySnapshot);

            return ListView(
              physics: const BouncingScrollPhysics(),
              children: <Widget>[
                Container(
                  margin: const EdgeInsets.only(top: 0.0, bottom: 16.8),
                  height: 724.8,
                  child: ListView.builder(
                    itemCount: querySnapshot.size,
                    padding: const EdgeInsets.only(left: 28.8, right: 12),
                    scrollDirection: Axis.vertical,
                    physics: const BouncingScrollPhysics(),
                    itemBuilder: (context, index) {
                      return Container(
                        height: 214.8,
                        width: 188.4,
                        margin: const EdgeInsets.only(right: 16.8, bottom: 50),
                        decoration: BoxDecoration(
                          borderRadius: BorderRadius.circular(9.6),
                          image: DecorationImage(
                            fit: BoxFit.cover,
                            image: CachedNetworkImageProvider(
                                querySnapshot.docs[index].data()['image'],
                                maxHeight: 200,
                                maxWidth: 200),
                          ),
                        ),

How can i list Firestore locations from closest to farthest?