Venice Marco Polo Airport: Take the ATVO Airport Shuttle (Line 35) to Piazzale Roma: about 20 minutes, roughly €10 one way with luggage. ACTV Aerobus 5 is the city-bus alternative, about 23 minutes and similarly priced, but ATVO is the better ride with bags. From Piazzale Roma, walk or change to a vaporetto. Do not take a private water taxi unless your hotel is on a canal and you are deliberately paying for the convenience: it is vastly more expensive. Alilaguna water buses are useful only if their stop is close to your hotel; they are slower than the bus.
Treviso Antonio Canova Airport: Use the ATVO Eurobus to Piazzale Roma, timed around flights: allow roughly 70 minutes and about €12–15. It is the sensible direct connection; a taxi to Venice is poor value. From Piazzale Roma, Venice becomes a walking-and-waterbus city.
Venezia Santa Lucia railway station: This is the station you want: it is on the island at the western end of the historic city. Your final transfer is on foot or by ACTV vaporetto from Ferrovia; Line 1 is the slow, scenic Grand Canal route, while Line 2 is often the more useful faster option. Do not assume a hotel is ‘near the station’ in suitcase terms—bridges and narrow lanes make even a short map distance laborious.
Venezia Mestre railway station: If your train ends at Mestre, continue to Venezia Santa Lucia rather than treating Mestre as Venice: frequent trains take about 10–12 minutes and cost only a few euros. Mestre is practical for cheaper hotels and early flights, but it is a mainland city, not the lagoon experience.