I spent 7 nights in Venice and, like Lola, didn’t take a gondola ride or drink in Piazza San Marco.
There are many guided walks.
We enjoyed taking the vaporetto to Torcello and walking down to the Basillica. We almost had the island to ourselves and it’s so different from Murano and Burano, which were heaving, despite getting there early.
We also took the vaporetto over to Lido, which, having roads and cars felt very different. We didn’t stay more than an hour, but as it was at the end of our week, it was strange to see. It’s more a locals place rather than tourist central and there were many very popular cafes and restaurants with not a tourist in sight.
I stayed in Cannaregio and enjoyed getting lost in the small streets. The Jewish Ghetto was nearby.
We took several vaporetto rides in loops around the various islands and some rides at night for a different feel. We had a 7 day vaporetto pass, although at many times it was as quick to walk, it was fun to take the boat.
I generally found the food in Venice to be disappointing. A great place for chichetti (tapas) and a good selection of wines was Cantina Aziende Agricole in Cannaregio, which doesn’t look much from the outside, but which was full of locals. For a quick lunch stop, Pasta & Sugo was good, overlooking floating market stalls in Dorsoduro.