My first stop in Italy was Rome, where I spent a full on week exploring some of the history on offer by the city. I doubt you could see it all in a month, let alone a week, but here are some of the places we visited.
The Colosseum was our first visit. It was great doing a tour, as they really went into the history of the place (and the palace next to it) in an interesting way. We only did two guided tours in our entire time in Rome, but I would definitely recommend them. This tour was in English (which my aunt didn’t really understand), then we did the Vatican tour in German (see below).