Timing for buying air tickets in Italy

As for timing, if you were planning to fly from Boise to Seattle and then Portland to Phoenix , when you you buy those tickets?

You could wait until on the trip, but likely pay more and have fewer choices

No help on airline suggestion, as my only "local" flight was with Alitalia

It wouldn't hurt to start shopping so you have an idea of what's available - you might look at ITA Airways, which is the Italian national carrier, in the process of being acquired, at least in part, by Lufthansa. You can also research on Google Flights, Expedia, etc. to see what other flights are available. For some of the European discounters, you may have to go to their proprietary sites. Maybe start looking in earnest to buy at the end of this year/early 2024.

Thank you - will check out your suggestions. I should have added that I have already purchased the “big” ticket - Vancouver to Venice return on KLM - I think a very good price for a changeable and refundable ticket. I felt it would be okay to wait for the internal Italian flights until much closer to the tour days (April / May).

I look for tickets as early as they're available and sign up for alerts with Skyscanner, etc., buying tickets when it seems like a good enough deal. This approach has never failed me and I've found that buying tickets 8-10 months in advance works. Maybe it's just dumb luck on my part, but I've never become annoyed because of a big price drop after I bought the flight.

We're looking at Poland in June 2024 so it's about time to shop for flights.

many flights within Europe are on budget carriers such as Ryanair or Easyjet. If you end up selecting a budget carrier you'll have a smooth experience if you keep in mind they really mean every condition they list on their websites. Carry-on bag size and weight, boarding pass, seat assignment, etc. Many larger international carriers kinda let things slide but the budget carriers don't. So follow all their rules and things will go fine.

April and May are busy times for Italians traveling within Italy due to quite a few holidays (and perhaps especially so for northerners going back home to Sicily), so I would not wait that long to start looking at tickets.

Have just been poking around on ITA and Ryanair and they are not showing flights as far out as my dates but will check periodically to see when they start to be available.
Thanks again!