We are from Ljubljana Slovenia, my husband received for his birthday from our sons a Flow hive. Looking for a Flow hive owner here in our country. We do need some advice, a hand from a nice person.
Welcome, Anamarija,
I hope somebody from your region finds you. Do you have a beekeeper’s club in the area? That will be a great place for advice and most clubs have a few mentors willing to give their time to a newcomer.
Of course we made a contact to a local Beeking association , very kind people indeed, but have no experience with flow hive. They are trying to show us a traditional way that we no nothing about. So we will learn first their way and try to figure out how to make it happen with FLOW HIVE.
The frames they have are 26x41 cm.
You might be on the way to becoming the flow hive mentor. 
Many traditional beekeepers were suspicious of the flow hive when it came out but those voices have calmed down now that it’s had a few years to prove itself.
The official Flow youtube channel has lots of videos that cover a lot of detail, and they have recently set up an education video site that gives a 30 day free access to new starters.
One of the youtube sites I watch regularly is Frederick Dunn. His presentation is always very clear and his Q&A videos cover a lot of detail. He has different types of hives, including Flow which seems to have become a favorite for him. There are other sites out there but Fred is my pick of them.