Thanks for comment.
I searched about selling prints in the streets but here they don't give permission for it. Only food, toys and clothes. Nothing else.
And if I know Germany well, I would need a certificate about history or turism I supose, to get permission to offer tours to turists. And I am sure they don't give permission to offer tours in the streets. The same way they don't give permission to offer portrait services for tourists in the streets (yes, I have tried).
The only thing they give permition is for selling handmade clothes, toys and food, and only in very feel places and very feel dates. And the line to get the permission is long. And they give permission only for 3 or 6 months. Even selling tshirts with my photos of touristic places in town they don't give permission.
The only best way to earn money in the streets if you don't sell food, toys and handmade clothes, is asking for money when you are homeless or play music hoping people will through some coins or buy your CD. Nothing else.
And to offer courses I would need open a business before even trying promote it to see if there is market for it. As I had to open a business even before have actually sold any print, just to be allowed to put price tags in my website.
I could try but it would have to be somewhere less burocratic (like in Croatia) and where I can experiment to see if works, registering my business and dealing with papers when I start actually have business, earning income, and not before.
France is not far from here but the towns nearby are very small. But maybe I could try there. But I habe heard that they are very burocratic too. I once tried to live in France but rent a room there is a nightmere, as well as open a bank account.
This is also the reason I prefer have a partnership with somebody who is better about marketing, business, red tapes, because I can't deal with all that on my own.