Issue with calculating the distance between two points on a map

I have an error issue that I haven’t been able to solve despite doing extensive research. In fact the similar examples I have found so far have been educational but I have not been able to make work. The example below I am hoping will be easy to fix as it is only producing errors with one line of code…

import SwiftUI
import CoreLocation
var currentLon = Double()
var currentLat = Double()
extension CLLocation {
    class func distance(from: CLLocationCoordinate2D, to: CLLocationCoordinate2D) -> CLLocationDistance {
        let from = CLLocation(latitude: from.latitude, longitude: from.longitude)
        let to = CLLocation(latitude: to.latitude, longitude: to.longitude)
        return from.distance(from: to)
    }
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations:    [CLLocation]) {
        currentLon = (locations.last?.coordinate.longitude)!
        currentLat = (locations.last?.coordinate.latitude)!
    }/*⚠️ Not sure if this function will work? (Update User Location coordinates on the move?)*/
}
struct Positions: Identifiable {
    let id = UUID()
    let name: String
    let latitude: Double
    let longitude: Double
    var coordinate: CLLocationCoordinate2D {
        CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    }
}
struct GameMapView: View {
    let from = CLLocationCoordinate2D(latitude: currentLon, longitude: currentLat)
    let to = CLLocationCoordinate2D(latitude: thisCardPositionLongitude, longitude: thisCardPositionLongitude)
    let distanceFrom = from.distance(from: to)
/*⚠️ ERRORS:
   1. Cannot use instance member 'from' within property initializer; property initializers run before 'self' is available.
2. Cannot use instance member 'to' within property initializer; property initializers run before 'self' is available.
3. Value of type 'CLLocationCoordinate2D' has no member 'distance'. */
    @State private var region = MKCoordinateRegion(
        center: CLLocationCoordinate2D(
            latitude: thisCardPositionLatitude,
            longitude: thisCardPositionLongitude),
        span: MKCoordinateSpan(
            latitudeDelta: 0.0001,
            longitudeDelta: 0.0001)
    )
    var body: some View {
        Map(coordinateRegion: $region,
            showsUserLocation: true,
            annotationItems: locations){ place in
            MapMarker(coordinate: place.coordinate,tint: Color.accentColor)
        }
            .edgesIgnoringSafeArea(.all)
        VStack {
            Print("Distance from Location: \(distanceFrom)")
            font(.largeTitle)
            padding()
        }