Ciao Sophie, from Firenze to Bologna x to Mestre or Venezia x to Trieste .Because of high season, advanced reservation is highly recommended ! Trieste is beautiful but hot in August.

Still far too early for Trenitalia timetables. However just check a similar day in the next few weeks to show the likely times and frequency - they won’t change much. Try at 90 days and then 60 and you will eventually find solutions.

Currently there is an hourly service to Venice with connections to Trieste. There will be a 10 euro res fee for Fir - VCE.