Venice is one of those places that you must explore on foot - you really don't have a choice. You will arrive by boat, and you will either walk or ride one of the water taxis. But the city is really walkable, it's not that big and if you take it a sestiere (section) at a time it is really easy to do. Try walking a sestiere each day. You will get the feel of the city this way. Find the squares around the churches, walk where the locals do. Take the gondola ride (even though it is pricey), because that is the thing to do. Grab a slice of pizza to go, sit in the square and watch the world go by, have a glass of wine and watch the boats on the Grand Canal. You might even catch a giant cruise ship passing!