json.go

func extractLatLng(data []byte) (float64, float64) {
  res := make(map[string][]map[string]map[string]map[string]interface{}, 0)
  json.Unmarshal(data, &res)
  
  lat, _ := res["results"][0]["geometry"]["location"]["lat"].(float64)
  lng, _ := res["results"][0]["geometry"]["location"]["lng"].(float64)
  
  return lat, lng
}

Unpacking the JSON into a struct like

type geojson struct {
   Results [] struct {
      Geometry struct {
         Location struct {
            Lat float64
            Lng float64
         }
       }
    }
 }

I believe would work.