Moving the bees in depends on how the Nuc grows, time of year, is the Nuc a Langstroth? The frames from the nuc if a lang, will just slip straight into the Flow Brood box when the time is right. You will need a little help/tuition or to join a group locally to get more hands on advice.
The complete Flow Hive comes with 2 Brood Boxes/Deep Supers… The Brood box is the standard size and the super’s are often called Mediums and then there are larger ones called Jumbo.
On the Flow hive the Super is the same size as the brood box. There is no rule to say brood boxes cannot be used for super’s so no big deal just means more honey from the larger surface area - but will take that bit longer to fill than normal Super’s.
Small = Medium /super’s for honey collection
Normal = Brood or Deep Super - bee rearing boxes
Jumbo = Deeper than normal Brood - Rearing or Very large Honey Collection - but would be way to heavy
The complete Flow comes with entrance, roof, Queen excluder - can’t remember if you get frames for the Brood box so probably need some of those - something to raise the Hive off the ground - breeze blocks, stand - what ever you plan needs to be sturdy. Probably some Wax sheets or wired wax sheets - Those are the basics - but I’m sure you’ll find more things to buy and use
If your in Canada you may need to think about ventilation and warmth for winter
Oh! And don’t forget to get some bees
Hope that helps