The training will take place at the Novotel Marseille Vieux Port.
The airport is located outside Marseille, the taxi from the airport to the hotel costs between 50 and 60€
There is a very convenient shuttle service from the airport to the central train station, with one departure every 15 minutes, and costs 8.5€.
Ater having reached the bus/train station, here is no direct way to reach the hotel by public transportation. The taxi from the station to the hotel costs about 10€. I would thus recommend to take the taxi to reach the hotel from the station.
Régie des Transports de Marseille: http://www.rtm.fr/