Civil ceremonies can occur in any location that's been approved by Italian authorities, indoors or outdoors. Many villas, castles, public gardens and town halls are approved for use. In smaller locations, a civil ceremony will be performed by the mayor or a town officer. An interpreter is required if neither person in your party speaks Italian, but they don't have to be an official translator. The amount of time required between declaring your intent to marry and your actual wedding date will vary by location.
The only church ceremonies that are legally performed without a civil component are Catholic weddings. One person in the couple must be Catholic. You should anticipate a longer planning period for a Catholic wedding, due to coordination between your local church, the Italian church, city officials and consulates. It’s a good idea to start planning six months before your anticipated wedding date.