My husband and I will be in Monterosso May 20-23. We would like a day trip to Pisa and Lucca. How difficult is this on our own without a car? Or do you suggest a tour and if so which?
I did this last summer on the train it is an 1 hour 30 minutes on the train Monterosso to Pisa You get on at Monterosso and Change at La Speizia
I found you can see Pisa in 3 hours or less
Pisa to Lucca is simple connected as well about an hour by train.
You really don't need a tour
use this site to help you see your options by train
https://www.rome2rio.com/
For actual train schedules, see www.trenitalia.com or the DB link at How to Look Up Train Schedules and Routes Online.
Pisa San Rossore station is closer to the sightseeing than is Pisa Centrale (with connector bus). Trains stop at both.
In addition to direct trains there are direct buses operated by Vaibus between Pisa and Lucca, described on pages 545 and 560 of Rick's Italy book, but not as fast as the train.