Hello and happy new year to all the riders on the forum

I'm starting to plan a trip riding to Italy from London at the end of June and, being my first long trip, I need some advice on a few things.

I'll be riding with pillion (wife)
I'm thinking 3 days to get there, 3 days staying (with family), 3 days ride back
Any suggestion on route, miles per day, costs, equipment needed/suggested, hotels on the way, and anything else that comes to mind?
As I mention, this is my first European trip, although I've been riding touring bikes for the last 10 years (embarrassing

), but I know some of you have done this several times and might be able to help preparing and planning.
Many thanks in advance