Clothing advice for October/November travel

Weather depends on where you're going, but I'd definitely opt for closed shoes over sandals at that time of year (unless you're spending the entire time far south).

We have traveled from North to South in both October and December. You will have days requiring layers and raincoats as well as days where a light shirt or sweater are fine. Lighter shirts and tops that can be layered under fleece or merino wool will give flexibility. Everything should be able to be worn on its own as well as over or under something for maximum utility. For December I had a long microfibre raincoat with a hood that was perfect. Might be overkill for Oct/Nov, but at least a good 3/4 length rainjacket is recommended. Hat, gloves, a scarf are good add ons. Smartwool socks, Gortex lined shoes, maybe a pair of sturdy flats or Mary Janes (I like Keen) as an alternative. Sandals you would wear so occasionally as to be a waste of suitcase space. I like jeans when I travel and always take two pair of lighterweight "trouser" jeans as well as a pair of wash and wear black pants that are a bit dressier.

Really depends on which end of the country you will be visiting.
Plan for warmer layers if north, around Florence and over to Venice. Warmer in Rome, but you can expect some rain. My experience in Rome first week of November a few years ago....wore Prana nylon pants and Puma shoes, and a zip up sweat shirt almost every day. Sun was out, but temps were cool. Wish I'd brought some sandals. I only had one pair of shoes with me and I ended up with a blister on a toe. My daughter was traveling with me and she had a pair of sandals that I wore the last day No need for shorts, but capri pants would be good. Pack a sweater for layering and always bring a hooded rain jacket. When we went, it was just for one week. We both packed in backpacking style backpacks, 45 ltr. Wore the same pants the entire time and switched out a few t-shirts. I packed both short sleeve and long sleeved tops. Bring a scarf as well to keep your neck or head warm should you encounter cooler temps. Just like in the US this year...the weather in Europe is not "normal". I kept checking the weather forecast for Rome and finalized my packing when I saw the weather for the week we were traveling. It's not a perfect way to do it, but it helped me decide what to bring and what to leave home.

Thank you, everyone! This is really helpful. We'll be flying into Rome but are just spending a day there. Most of our two weeks will be spent in Florence, Venice and the Cinque Terre.