Three years ago this thread has some ideas:=
https://community.ricksteves.com/travel-forum/italy/bookstores-in-venice
Here is what I found....Good luck... Libreria Marco Polo..This
friendly bookstore specialises in travel, from guides and maps to
works of fiction. There's a good selection of guidebooks and fiction
in English. Address..Castello 5469, salizada San Lio..Area Venice
Transport Vaporetto Rialto..Open 9.30am-1pm, 3-7.30pm Mon-Sat. Lists
that they have English travel books.. Studium ...This shop stocks a
wide selection of works on Venice, as well as travel books and novels
in English..Address..San Marco 337C, calle Canonica..Area
Venice..Transport Vaporetto San Zaccaria..Open 9am-7.30pm Mon-Sat;
9.30am-1pm, 2-6pm Sun. Libreria Mondadori..Venice's only mega-bookshop sprawls over three floors. The ground floor is reserved for exhibits,
book signings, events and courses of various kinds. Upstairs, there's
a selection of books in English. Address San Marco 1345,...salizada
San Moisè..Area Venice..Transport Vaporetto San Marco Vallaresso..Open
10am-7.30pm Mon-Sat; 11am-7.30pm Sun