Travel from Trieste port to Hotel dalla Mora

A little more information would be helpful.
Is your hotel in Venice? If so, take the train to Venice S Lucia, about 1 1/2 hours. Then take the vaporetto (water bus) to the closest stop to your hotel and walk to your hotel. The hotel can provide directions for you from the train depot.
How long will you stay in Venice? You may want to buy a vaporetto pass. If it's just an overnight stop before you fly out early in the morning, you might want to stay near the airport.
How much luggage are your going to have? There are no porters so you have to handle it yourself. Easy to do with a carryon size suitcase and personal item. If you have lots of luggage you may want to get a water taxi, but be forewarned they are expensive and you may still have to walk to your hotel.
Look at Google maps for locations. Here's information about the Vaporetto https://avm.avmspa.it/it/content/vaporetto TrenItalia website is https://www.trenitalia.com/en.

The Hotel dalla Mora is in the interior of the island and no way to get there without a good walk from the train station. If you have a lot of luggage, good luck. Maybe find a hotel closer to the Grand Canal.

The Continental is an easy walk from the train station with no bridges to cross.

The Hotel dalla Mora website indicates you can hire a luggage porter at the station to haul your luggage for a price. Or take a water taxi for about 75 EUR.