How do I find out if Northern Italian ancestors' information has been indexed?
There are a couple of things you can do. If you're interested in particular ancestors, and you know enough details (name, as well as additional details such as birth year and place), you can do a record search. On the main menu at the top of FamilySearch.org, choose Search, then Records, which will take you to https://www.familysearch.org/search/ . Then you can enter the information you know about one of your ancestors and see if there are matching records. If there are indexed records that match your people, you should see some matches.
You can also look in the FamilySearch Catalog. That is also on the main Search menu under Catalog, which takes you to https://www.familysearch.org/search/catalog . Then you can enter a place. For example, my northern Italian ancestors are from Miola. When I enter that place, I can see that there are Catholic Church records for that place. You could do a similar search for whatever place you are interested in (it can be a town or a region). Note that some records may have images but are not yet indexed. The Catalog will help you see those details.
And there are currently over 40 Italian indexing projects. You can see what is coming, and you can help, if you want, with an indexing project. https://www.familysearch.org/search/location/continental-europe/italy
One thing to keep in mind: the Catalog is at this point a full two years out of date, so it doesn't know about any indexes published in the last two years. If your research is in an area or record set that is actively being indexed, then even if the catalog only has a camera icon for a particular film, it may be worth your while to plug its number into the "Image Group Number (DGS) or Film Number" field of Search - Records.
Thank you to all for your help! The "community" is a great resource. I haven't found my Benuzzi late 1700's ancestors from Dro,Trento Italy as yet, but I will keep searching. My daughter looked at microfilm at SLC in 2014 and found names and birth dates for some but earlier ancestors only with names, specifically my 3rd great grandfather and grandmother.
Again, thank you!