The closest airports are Milano-Malpensa (MXP) and Milano-Linate (LIN). From MXP you can get to Milan Central Station by taking the Malpensa Express (you can buy tickets here). The workshop will be held in via Festa del Perdono 7, at walking distance from the Missori-Università degli Studi and Duomo underground stations. One can get to the university also by tram (lines 12, 16, 19, 24, 27).
Some hotels reasonably close to the university are the Hotel Canada, the Palazzo Porta Romana, the Grand Visconti Palace, the Uptown Palace, and the Mediterraneo. There are also plenty of options on airbnb.