Hi Tord, thanks for the introduction. Welcome to the forums.
You know our stance on determining how to get started (workflow first!) and you can always read up on recent posts on these forums on this very subject. It’s highly unlikely that you are currently holding the knowledge and experience to decide on a high end controller. I’d say get one of the good starter controllers and upgrade when you are ready. The RZ is an expensive and impressive bit of kit, but not something I would put in the hands of a beginner.
Also the RZ is pretty much RekordBox DJ-only and should only be your choice if you know 100% for sure that this is the software that is right for you. Something else you can’t really know yet.
So, save yourself a lot of money and potential disappointment by doing your “homework”, determining workflow, picking matching software and then a matching starter controller. Treat yourself to the How To Digital DJ Fast course so prevent lots of trial-and-error. It will show you what to practice and how to practice it best.
Final word on stepping into a DJ “booth”. While it’s good not to overextend yourself, the only real way to learn how to please the crowd is by being out in front of one. You can NOT learn that skill practicing alone. So I’d say get the course and in 2-3 months you will be ready to play your first house party. And if it’s only 15 people in a living room, go do it. It’s experience you can’t get from a course or youtube vids.