Please Help with 3 week Europe Itinerary!!

We leave from America on June 3rd and land in Frankfurt Germany on June 4th at 10:45 AM. Then we plan to eat lunch and catch a train to Paris. This is an idea of what we want to do, but I was curious if I am not spending enough time in each day?? it’s my first time in europe and i want to see as much as I can. we are flying into frankfurt cuz it’s the cheapest ticket we could get and we have a 22 day eurorail pass. Any suggestions are appreciated!! Here’s the plan:

Paris, June 4-7 Switzerland, 7-10, Florence, 10-13 Rome, 13-17 Sorrento, 17-23 Fly back up to Frankfurt 23 evening Fly home 24.

edit: The plan is to base in Sorrento and do day trips to Pompeii, Naples, Positano, Capri!