(Waving at Carrie)
A welcome to the forums from one of your MN neighbors! You're going to have so much fun figuring out where to spend your 4-5 weeks abroad! Along with browsing the threads here, the library is an excellent and inexpensive place to acquire resources for your research. Check out a variety of guidebooks and travel-related CDs. There are also tons of youtubes and other online resources.
What I wouldn't do is take minutiae like hours, ticket prices, transport pricing, sightseeing passes, etc. as gospel as much can (and likely will) change by 2023. At this point, just figure out where you want to go, how long to stay in each place, what sorts of things you and your young people wish to see, and most efficient ways of moving your tribe around.
Those young folks? Get them involved! This is a priceless opportunity for them to start learning what goes into researching and executing their own trips in the future. It also helps keep the whine factor down if they've had a hand in choosing sightseeing/activity choices versus just being herded about ...not that your children aren't or won't be cheerful, flexible travelers. 😉 It's just more fun if all 5 of you can enjoy terrific family discussions and collective dreaming about your wonderful opportunity.
As far as the forums, the more you can tell us about your family's interests and travel experience to date, the better posters can help you plan a trip you'll be reminiscing fondly about for many, many years to come.