Firenze is well connected to the main European cities through the Amerigo Vespucci international airport (code FLR) that can be reached in about 15-30 min from the city center with the bus-shuttle or by taxi. It is also possible to fly to Pisa (PSA) or Bologna (BLQ) and then reach Firenze by train.
The main railway station, Firenze Santa Maria Novella, is located in the city center, not too far from the conference venue (about 1.2 km). For train timetables and reservations you may consult the web site of the two companies operating on the Italian Railways, namely Trenitalia and Italo. Transportation to/from the station is possible by bus or taxi. Since the city center is relatively small, it is also likely that your hotel will lie close to the train station and you may afford walking there - unless you have a heavy luggage with you.