A train. Regular and local trains Moscow - Kaluga-1 depart from Kievsky railway station. Local suburban train schedule you can find here https://clck.ru/FwvPn
. Travel time is about 2,5-3,5 hours depending on the train. There are two train stations in Kaluga. You have to choose Kaluga-1 station because the bus (to Ferzikovo) you need departs from this station square. If you still chose Kaluga-2 station you can go by taxi or local bus No.10 from Kaluga-2 to Kaluga-1 station. It will take about 30 min.A bus.
Buses Moscow - Kaluga depart from the bus terminal at the metro station "Tyoplyi Stan" (orange underground line) and arrive at a bus station which is situated next to Kaluga-1 station.
There are also flights
to and from Kaluga city from and to Moscow, Petersburg, etc. But they are not daily. If you have your return flight from Moscow Vnukovo on Sunday night after the course you may be interested in a flight KLF-VKO 23:00-23:40. Taxi.
You can get to the course place from the airports or from Kaluga via taxi by apps. UberRussia (please mind that it's a separate app from international Uber!), Yandex taxi, Maxim, Rutaxi are recommended. For destination point try to paste or type "МПБ Калужский ретритный центр"