We went here in July with our teenage daughter and friend just for a few hours. We just booked the tower because that was all they were interested in. It was great, the access is straight forward and you climb the tower. One big suggestion don’t forget to put your bag in the storage lockers by the toilets as they are not allowed up the tower. The view was spectacular and you can stay up for hours if you want.
We parked at the free parking and walked into Pisa only a 10 minute walk super easy