Question Best Way to Travel by Train from Vienna to Florence?

Hello. I will be in Vienna in May to visit a relative before going on to Florence for a preplanned trip. I'm considering taking the train for this journey but have never traveled by train between these two cities before. Does anyone have experience with this route? How long does it usually take, and are there any scenic stops or tips you'd recommend along the way? Also, should I book tickets in advance, or is it okay to buy them on the day? Any advice would be much appreciated!