I live in Slovenia and I want to take a trip with my friend to Vienna. I got a valid ID and passport and I could take a bus or a train there.
But the problem is the stay. Is it possible to stay 2 nights as a minor? Do youth hotels or something like that exist?
I definitely suggest contacting the hotel in advance because most of them might have some sort of guest age regulations. It'll probably be so that your parents might have to fill in some form or make it known in any way that you have permission to travel by yourself. I'm not completely familiar with minors travelling unaccompanied within the EU, but from my country (Europe, non-EU) to other countries, minors need to obtain a document which is a proof parents have agreed to let the minor go somewhere unaccompanied.
Look into it not just with the hotel, but perhaps some sort of local travel agency or an embassy even to see what they have to say.