How much time to go from Trieste to lido di jesolo venice?
I would allow at least 3.5 hours for this trip on public transport to provide for time at the transfer points. More if you take a slow train.
It isn’t entirely clear which direction you want to go, but just reverse the course if you’re starting in Trieste airport - take the shuttle to Monfalcone, the train to Mestre, and the bus from Mestre to Lido di Jesolo. The bus station is right next to the train station in Mestre.
The best way to get to the Trieste airport from Lido di Jesolo is to take the bus to Mestre, transfer to a train to Monfalcone, and then take the APT bus (#10) to the Trieste airport.
The bus to Mestre takes about 50 minutes. You can find a schedule at: http://www.atvo.it/orari.php?ld=orari.php click on the link next to line 10A
You could also take line 9 to Udine and get the train or a bus there to the airport, but the trip is 2 hours and there are only a couple of busses a day.
The train from Mestre is the same one you would take to get to Trieste, but Monfalcone is closer to the airport. There are a couple of trains an hour; the trip is around an hour and a half on the faster trains. The Monfalcone shuttle bus to the airport runs every 20 to 25 minutes.
You can check the train schedules at: http://www.trenitalia.com/en/index.html
Lido di Jesolo is very nice. Most of the hotels have restaurants, some with very good views as well. You might try Cozze e Gamberi or Ipanema.