In Italy, you can opt for a religious ceremony and the procedure varies according to your specific religion. I would like to remind you that Italy is predominantly a Catholic country and the procedure to get married in Italy is still very conservative. This is because there are not many Catholic Churches that will conduct marriage ceremonies for non-Italians. Please check feasibility in advance. In fact, priests usually give priority to couples who belong to their parish. It is important to communicate constantly with the priest of the church, who will make all the proper checks before allowing you to marry with a catholic rite.
There are plenty of churches and bell towers in Venice, each of them embodies the art and history of this wonderful city. If you have been to Venice, then you know how many churches there are without looking at a map, simply by walking around. Literally an embarrassment of riches!!