There are many accommodation options in Bolzano and surroundings. The majority of accommodations in Bolzano are at a walking distance from the main conference venue, or at most at a 10-15 minute distance by public transport or bike. We can recommend checking on https://www.booking.com and particularly on https://www.bookingsuedtirol.com.
When choosing accommodation, it may be useful to check whether the hotel is a partner hotel for the Bolzano Bozen Card. The card is issued free of charge by participating hotels for the duration of the stay and includes free public transport across South Tyrol, including regional trains, buses, selected cable cars, the Mendola funicular, and the Renon railway. The full Bolzano Bozen Card also offers additional benefits such as selected guided tours, bike rental, events, and discounts with partner businesses. More information is available here: https://www.bolzano-bozen.it/en/bolzano-bozen-card/.
For PhD students on a tight budget, we recommend the Bolzano Youth Hostel, which offers affordable accommodation just a short walk from the conference venue: https://www.youth-hostel.bz/en/bolzano/youth-hostel/.
Alternatively, please consult https://www.booking.com or https://www.airbnb.com.