I went on a solo trip to Italy and Rome last month. I am sharing my Italy Itinerary to guide first-time visitors to Europe. Make your backpack with this Backpacking Europe Packing List
One thing that was common in every place was beautiful churches and Frescos there. In Italy, they always believed in the balance so if a church is beautiful from outside, it's going to be very simple inside and vice versa.
1. Rome - For Rome trip, I think 3 to 4 is enough to make your trip plan . If possible stay near Trastevere and not in the centre if you want peace else near Colosseum you will find many budget hotels and places to eat. All the attractions are close to the centre and finding Indian food us damn easy in Rome.
2. Assisi - 2 days - This was my favourite city as it was very peaceful and being on a hill, very beautiful. Loved it.
3. Florence - 3 days. It was like Rome but a little less touristy. Food was great, great bars and great people. From Florence I also went for a day trip that included Siena, San Gimignano and wine tasting trip ( can find it easily on trip advisor), it was a little rushed but not bad.
4. Venice - 2 days - I didn't like it that much but it was a solo trip maybe that's why it seems fewer attractions for me. In the evening it looked beautiful though, sit and relax.
5. Sant Agnello (south Italy) - 6 days - this was my location to access Sorrento, Positano Amalfi and Pompeii. This place had the best food and the cheapest. Positano was beautiful but be ready to walk a lot down and up the hill, the same goes for Amalfi. Sorrento was good nothing extraordinary but limoncello is to die for, don't miss it. Pompeii is a must.
All the best!
Trip Cost: 28k INR flight tickets, 1.7lacs including train tickets, hotels (stayed in hotels with private room in every city, no hostels), Food & Drinks (30-40% of this .I spend a lot on this because for me it's one of the most important parts of experiencing any place) and attractions.