I've been to Venice several times.
I used google maps very effectively to figure out paths and vaporettos.
If you like museums there are passes that combine museums, vaporetto passes, and church passes. I really enjoyed the Choral Pass - which gets you into many of the churches with amazing art.
https://www.veneziaunica.it/
The Peggy Guggenheim museum is amazing if you enjoy modern art. Last spring we saw it was going to be raining one day, so we pre-booked time slotted tickets and were able to bypass the very long line. (Everyone else figured a museum was great for a rainy day - but had to wait in line.)
Another suggestion is to do a tour of the Jewish Ghetto. It was not at all what I expected and gave a good history of how Venice was different, in many ways, than the rest of Italy during WWII.
Don't be afraid of vaporettos. Be sure you frank your ticket (or phone QR) before you board and you're good to go.
Final tip: If you want a less expensive gondola ride, or just need to get across the grand canal and are between bridges, consider a Traghetto di Gondola. It's only 2 euros. These are the same type of boats (without the fancy seats) and two rowers, one a trained gondolier, the other an apprentice. They literally just cross between fixed points. Locals stand up in the boat. Often there are up to 10 people on the boat. Part of the rigorous training to become a gondolier requires training on the Traghetto under a gondolier.