One ticket to..., please.
'Biglietto' — 'bi-LYET-to'. Three syllables; 'gli' gives a liquid 'ly' sound.
The most fundamental ticket-buying phrase — state the destination or event after 'per'. Use at any counter: train, bus, cinema, museum.
'Un biglietto' means 'one ticket'. 'Per' means 'to/for' here. Adding 'per favore' (please) is always appropriate. The seller will then ask about travel date, class, or show time depending on the context.
Due biglietti per Roma, per favore.
Two tickets to Rome, please.
Change 'un' to the number you need.
Un biglietto per lo spettacolo delle otto.
One ticket for the eight o'clock show.
For theatre or cinema — specify the time.
Tre biglietti per il museo, grazie.
Three tickets for the museum, please.
Museum entry — often specify adult/child after this.
In Italy, buying tickets in person at the counter ('biglietteria') is still common and valued — Italians appreciate the human interaction. However, self-service machines and apps are increasingly standard, especially for trains.